>>> TONIGHT, THE >>> TONIGHT, THE CRITICAL HOURS FOR PRESIDENT BIDEN AS THE RACE TO DO DEBATE DAMAGE CONTROL INTENSIFIES. THE PRESIDENT TODAY ACKNOWLEDGING, "I SCREWED UP." IN OUR NEW REPORTING, HE IS PRIVATELY TORN BETWEEN ACCEPTANCE AND DEFIANCE IN THE FACE OF CALLS TO WITHDRAW, NOW SAYING, ACCORDING TO SOURCES, HE WANTS TO GET MORE REST, AND REVEALING HE SAW A DOCTOR AFTER THE DEBATE, EVEN AFTER THE WHITE HOUSE SAID THAT WASN'T THE CASE. FORMER PRESIDENT TRUMP NOW WEIGHING. IN. >>> ALSO TONIGHT, THE HUGE WILDFIRE IN CALIFORNIA. TENS OF THOUSANDS EVACUATED FROM THEIR HOMES. JULY 4th FESTIVITIES CANCELED, ALL DURING A DANGEROUS HEATWAVE. MORE THAN 140 MILLION AMERICANS UNDER ALERTS TONIGHT. >>> HURRICANE BERYL'S PATH OF DESTRUCTION, RIPPING UP PARTS OF JAMAICA, NOW TAKING AIM AT MEXICO. SO IS TEXAS NEXT? WE'RE TRACKING IT LIVE. >>> THE LATEST ON LAW ENFORCEMENT ON HIGH ALERT AT HOLIDAY CELEBRATIONS ACROSS THE COUNTRY. >>> AND THE NEWS JUST COMING IN. TWO CONFIRMED SHARK ATTACKS, ONE IN FLORIDA, ANOTHER IN TEXAS. >>> THE PHONE CALL BETWEEN PRESIDENT BIDEN AND ISRAELI PRIME MINISTER NETANYAHU. IS THERE OPTIMISM FOR A POTENTIAL CEASEFIRE? WE'VE GOT THE NEW REPORTING. >>> THE FBI NOW INVESTIGATING CHINESE OLYMPIC SWIMMERS WHO FAIL DOPING TESTS AND WHO ARE SET TO COMPETE IN PARIS JUST THREE WEEKS FROM NOW. >>> AND THOSE JULY 4th HOLIDAY SALES. WHAT EXPERTS SAY IS REALLY A DEAL NOW AND WHAT'S WORTH WAITING FOR. >> Announcer: THIS IS . >> GOOD EVENING. I'M HALLIE JACKSON, IN FOR LESTER. AND WE'RE COMING ON THE AIR TONIGHT WITH PRESIDENT BIDEN PUBLICLY LOOKING TO REASSURE AMERICA, AS PRESSURE BUILDS AHEAD OF WHAT COULD BE THE MAKE OR BREAK WEEK OF HIS POLITICAL LIFE. BUT PRIVATELY, A STARK ACKNOWLEDGMENT HE'S GOT TO MAKE SOME CHANGES AND MAKE THEM SOON. MULTIPLE SOURCES TELL NBC NEWS THE PRESIDENT TOLD DEMOCRATIC GOVERNORS HE WANTS TO GET MORE SLEEP AND DO FEWER EVENTS PERHAPS LATER IN THE EVENING, A NOD TO THE FATIGUE THAT HIS AIDES HAVE PARTIALLY BLAMED FOR THAT DEBATE PERFORMANCE ONE WEEK AGO, WIDELY PANNED AS DISASTROUS. YOU SEE THE PRESIDENT JUST MOMENTS AGO CELEBRATING THE FOURTH OF JULY AT THE WHITE HOUSE. IT'S ALL HAPPENING AHEAD OF A HIGH-STAKES INTERVIEW TOMORROW AND PRESS CONFERENCE NEXT WEEK. A LOT OF PEOPLE WANT TO KNOW THE BOTTOM LINE. WILL THE PRESIDENT BOW OUT OF THIS RACE? HE SAYS NO, THAT HE IS IN IT TO WIN IT. BUT TONIGHT, SOME IN HIS OWN PARTY SKEPTICAL WINNING WITH HIM IS EVEN POSSIBLE. OUR MONICA ALBA REPORTS. >> Reporter: PRESIDENT BIDEN TONIGHT CELEBRATING OUR NATION'S HISTORY. >> HAPPY INDEPENDENCE DAY! >> Reporter: WITH HIS POLITICAL FUTURE ON , AS SOUR TELL NBC NEWS THE NEXT FEW DAYS OF HIS CAMPAIGN ARE CRITICAL AFTER LAST WEEK'S DISASTROUS DEBATE PERFORMANCE. WHICH THE PRESIDENT ACKNOWLEDGED IN A RADIO INTERVIEW THAT AIRED TODAY. >> I SCREWED UP. I MADE A MISTAKE. THAT'S 90 MINUTES ON STAGE. LOOK AT WHAT I'VE DONE IN 3.5 YEARS. >> Reporter: MR. BIDEN INSISTING HE IS COMMITTED TO STAYING IN THE RACE. >> YOU GOT ME, MAN. I'M NOT GOING ANYWHERE. ALL RIGHT. >> Reporter: THE PUBLIC CONFIDENCE COMES AS NBC NEWS HAS LEARNED THE PRESIDENT IS PRIVATELY TORN BETWEEN DEFIANCE AND ACCEPTANCE AMID CALLS TO STEP ASIDE, ACCORDING TO FOUR PEOPLE FAMILIAR WITH THE MATTER. SIGNALING IN SOME CONVERSATIONS WITH ALLIES, AIDES, AND FAMILY MEMBERS THAT THE BLOWBACK MAY GROW TOO LARGE TO OVERCOME. >> HE JUST QUIT, YOU KNOW. HE IS QUITTING THE RACE. >> Reporter: FORMER PRESIDENT TRUMP MADE THOSE FALSE CLAIMS IN A VIDEO HE SHARED ON SOCIAL MEDIA, IN WHICH HE ALSO SPECULATED OVER VICE PRESIDENT KAMALA HARRIS BECOMING THE DEMOCRATIC NOMINEE. >> I THINK SHE IS GOING TO BE BETTER. SHE'S SO BAD. SHE IS SO PATHETIC. SHE'S [ BLEEP ]. >> Reporter: THE BIDEN CAMPAIGN SLAMMING THOSE COMMENTS, WRITING "NO, DONALD, WHAT IS BAD IS RUNNING ON A PLATFORM OF YOUR REVENGE AND RETRIBUTION." THE VP AND PRESIDENT BIDEN MET LAST NIGHT WITH MORE THAN 20 DEMOCRATIC GOVERNORS, NOW RALLYING AROUND HIS CANDIDACY. >> I BELIEVE IN THIS MAN. I BELIEVE IN HIS CHARACTER. I BELIEVE THAT HE HAS BEEN ONE OF THE MOST TRANSFORMATIVE PRESIDENTS IN OUR COLLECTIVE LIFETIME. >> Reporter: CALIFORNIA GOVERNOR GAVIN NEWSOM CAMPAIGNING IN MICHIGAN TODAY, CONFIRMED DETAILS OF THAT WHITE HOUSE MEETING IN WHICH PRESIDENT BIDEN SAID HE MAY LIMIT EVENTS IN THE EVENING TO GET MORE SLEEP. WHEN ASKED BY ONE OF THE GOVERNORS WHETHER HE HAD SEEN A DOCTOR FOLLOWING THE DEBATE, THE PRESIDENT CONCEDED HE HAD A BRIEF CHECKUP A FEW DAYS AFTER AND WAS FINE, ACCORDING TO TWO SOURCES IN THE ROOM. CONTRADICTING HIS OWN PRESS SECRETARY, WHO EARLIER IN THE DAY SAID -- >> NO, HE WAS NOT CHECKED BY THE DOCTOR. >> MONICA JOINS US NOW FROM THE WHITE HOUSE. MON, TALK US THROUGH THE INTENSE SPOTLIGHT ON THE PRESIDENT'S NEXT 24 HOURS. >> Reporter: WELL, TOMORROW, HE'LL APPEAR IN THAT FIRST TELEVISED INTERVIEW SINCE THE DEBATE, LOOKING TO REASSURE VOTERS AND LEADERS WITHIN HIS OWN PARTY. BUT SOME ALLIES OF THE PRESIDENT ARE SAYING ALREADY THAT JUST ONE SITDOWN MAY NOT BE ENOUGH TO ADDRESS THEIR CONCERNS. HALLIE? >> AND MONICA, I'VE HEARD FROM CAMPAIGN SOURCES PUSHING BACK ON THE POLLING SHOWING A BIT OF A DIP FOR THE PRESIDENT. BUT ELECTED DEMOCRATIC LEADERS ARE ALSO LOOKING TO SEE WHERE DONORS GO. AND THERE IS MOVEMENT ON THAT FRONT NOW? >> Reporter: WE'RE STARTING TO SEE SOME BIG DOLLAR DONORS, INCLUDING REED HASTINGS, WHO COFOUNDED NETFLIX, CALL ON THE PRESIDENT TO EXIT THE RACE, WHILE BIDEN CAMPAIGN OFFICIALS INSIST THEY'VE SEEN SOME STRONG GRASSROOTS SUPPORT IN THE PAST WEEK, THOUGH THE PR HALLIE? >> MONICA ALBA LIVE AT THE WHITE HOUSE, THANK YOU. >>> TONIGHT'S OTHER TOP STORY, THAT BLISTERING HEATWAVE PUTTING MORE THAN 140 MILLION OF US UNDER ALERTS, THE DANGEROUS TEMPERATURES MAKING IT THAT MUCH HARDER TO FIGHT THAT HUGE WILDFIRE FORCING TENS OF THOUSANDS TO EVACUATE AND CANCELING FOURTH OF JULY PLANS IN NORTHERN CALIFORNIA. WE HAVE TEAM COVERAGE TONIGHT INCLUDING AN UPDATE ON DEADLY HURRICANE BERYL AS IT POSSIBLY HEADS TOWARDS TEXAS, BUT WE START WITH STEVE PATTERSON IN THE FIRE ZONE. >> Reporter: TONIGHT, STIFLING HEAT SUPERCHARGING A FIELD OF FIRE IN NORTHERN CALIFORNIA AS CREWS RACE TO CONTAIN THE FLAMES. STATE OF EMERGENCY AT THE THOMPSON FIRE, NOW MORE THAN 3500 ACRES. CREWS FINALLY ABLE TO GET A FOOTHOLD AFTER A DAY OF FAVORABLE WINDS, ONLY TO FACE MORE EXTREME HEAT. >> SO THOSE WINDS HAVE STOPPED, WHICH IS HUGE, BUT THE TEMPERATURES ARE ACTUALLY INCREASING. WE'RE IN THE 110, EVEN HIGHER. SO THAT TAKES A HUGE TOLL ON FIREFIGHTERS WORKING WHEN IT'S THIS HOT. >> Reporter: THE FLAMES TEARING THROUGH SEVERAL STRUCTURES IN 100-PLUS-DEGREE TEMPERATURES. LYNETTE BAILEY THREW EVERYTHING IN HER CAR, GETTING HER 90-YEAR-OLD DAD TO SAFETY AT A NEARBY SHELTER. >> IT WAS PANIC, BECAUSE MY DAD DIDN'T WANT TO LEAVE. AND I TOLD HIM YOU GOT TO GET IN THE CAR RIGHT NOW. >> Reporter: BUT BECAUSE THERE IS NO ROOM LEFT FOR HER DOG, SHE SPENT THE LAST TWO DAYS OUTSIDE IN THE HEAT. >> IT'S REALLY SAD. YOU DON'T WANT TO BE LIVING OUT THERE IN THE 108 DEGREES. I'M MORE WORRIED ABOUT MY DAD. >> Reporter: ACROSS ABOUT THE COUNTRY THIS FOURTH OF JULY, MORE THAN 148 MILLION AMERICANS UNDER HEAT ALERT. >> IT HAS BEEN SWELTERING. >> Reporter: FROM THE NORTHWEST TO THE SOUTHEAST, RALEIGH TO HOUSTON, PHOENIX TO PORTLAND, SEVERAL CITIES POISED TO SET NEW DAYTIME HIGHS. IN NEVADA, LAS VEGAS IS EDGING CLOSER TO SHATTERING ITS ALL-TIME RECORD, 118 DEGREES. >> HOW AM I GOING TO SIT OUT HERE IN THE HEAT? IT'S NOT MY DEAL. >> Reporter: BACK IN NORTHERN CALIFORNIA, MANY JULY 4th CELEBRATIONS CANCELED, FACING FIRE DANGER SO HIGH, ANY SPARK COULD SPELL DISASTER. IN THE BURN ZONE, THOUSANDS OF BRAVE MEN AND WOMEN BAKING IN THE WEIGHT OF THEIR OWN GEAR. >> IT JUST MAKES THINGS TOUGHER. >> Reporter: SURROUNDED BY FIELDS OF DRY TINDER, RUSHING TO KNOCK ONE FIRE DOWN BEFORE THE NEXT ONE SPARKS. >> AND STEVE JOINING US NOW. SO STEVE, GIVE US SOME GOOD NEWS. ARE THINGS STARTING TO LOOK ANY BETTER WHERE YOU ARE TONIGHT? >> Reporter: YEAH, HALLIE, THE WINDS HAVE FINALLY LAID DOWN, ALLOWING THE FIREFIGHTERS TO GET SOME ONE OF A HOLD. NOW 7% CONTAINMENT ON THIS FIRE, BUT IT IS ANOTHER DAY OF 110-PLUS DEGREE WEATHER JUST FUELLING THIS FIRE. HALLIE? >> STEVE PATTERSON, THANK YOU. >>> IN THE CARIBBEAN, HURRICANE BERYL REMAINS A POWERFUL CATEGORY 2 STORM AFTER SMASHING ITS WAY ACROSS JAMAICA, IN ALL LEAVING NINE PEOPLE DEAD IN THE REGION AS THE STORM NOW MOVES TOWARDS MEXICO AND MAYBE TEXAS. SAM BROCK IS ON THE GROUND IN JAMAICA. >> Reporter: HURRICANE BERYL TONIGHT CONTINUING ITS TEAR THROUGH THE CARIBBEAN. NOW JUST PAST GRAND CAYMAN, THE MASSIVE STORM SHAKING TREES AND CHURNING WAVES. THIS VIDEO TAKEN BY NOAA INSIDE THE HURRICANE THIS WEEK, REVEALING THE STORM'S POWER. LAST NIGHT, HURRICANE BERYL BATTERING JAMAICA, WHERE OFFICIALS ALREADY CONFIRMED TWO DEATHS IN THE COUNTRY, BOTH VICTIMS IN THEIR 20s, LEAVING THE NATION REELING. >> WAKING UP THIS MORNING TO ALL OF THIS IS LIKE -- IT'S OVERWHELMING. >> Reporter: ON TREASURE BEACHR SEASIDE OASI, JAMAICAN OFFICIALS TELL US THE DEVASTATION IS WIDESPREAD. >> HOMES DAMAGED. HEALTH CENTERS, CHURCHES, LOST THEIR ROOFS COMPLETELY. >> Reporter: JUST THE RIDE TO GET OUT HERE FEATURES TREES CARVING UP ROADWAYS, POWER LINES IN EVERY DIRECTION, AND OBLITERATED HOMES. >> HOMES BLOWN. YOU'RE SAYING THE ROOFS? >> THE ROOFS, YEAH. >> Reporter: ALL OF IT LEADING TO THIS. IT'S HARD TO DESCRIBE THE MAGNITUDE OF THE LOSS HERE, BUT HERE IS AN EXAMPLE. THIS IS A HOTEL WITH 100 PLUS STAFF MEMBERS THAT IS ONE BUSINESS ON ONE STRETCH OF STREET ON TREASURE BEACH. AND IT'S NOT JUST BIG BUSINESS FEELING THE PAIN. WHAT DO YOU FEEL EMOTIONALLY WHEN YOU LOOK AT YOUR BUSINESS? >> MAN, I FEEL SO DEVASTATED. >> Reporter: HERMAN MAXIM RUNS P & A FRUIT STAND RIGHT IN FRONT OF THE HOME HE SHARES WITH MADRONA MORRIS, WHICH IS PRACTICALLY UNINHABITABLE NOW. WERE YOU SCARED YOU MIGHT NOT SURVIVE? >> YES, YES, I WAS PRAYING OUT LOUD, CALLING TO JESUS, ASKING HIM TO CALM THE STORM. >> Reporter: JAMAICANS FEELING THE PAIN OF THE HURRICANE THAT DON'T EVEN MAKE LANDFALL, BUT IS LIKELY TO DISRUPT THEIR LIVES FOR MONTHS. HOW LONG DO YOU THINK IT WILL TAKE TO GET BACK TO WHERE YOU WERE? >> TO WHERE WE WERE? THAT'S A HARD ONE. >> Reporter: FOR MANY TONIGHT, ACCESS TO BASIC RESOURCES IS AN ISSUE, FROM FISH TO FUEL. LOOK AT THE LINES AT THE GAS STATION RIGHT NOW. THIS HAS BEEN GOING ON ALL DAY LONG. AND OFFICIALS SAY ONE OF THEIR OTHER PRIORITIES TONIGHT, CLEARING HIGHWAYS THAT ARE BLOCKED TO MAKE SURE THAT PEOPLE WHO NEED TO GET TO HOSPITALS CAN DO SO. HALLIE? >> SAM BROCK IN JAMAICA FOR US, THANK YOU. >>> LET'S BRING IN METEOROLOGIST MICHELLE GROSSMAN. MICHELLE, WHERE IS THE STORM HEADED NEXT? >> HI THERE, HALLIE. WE'RE LOOKING AT A VERY STRONG POWERFUL 2 STORM. ACROSS THE GULF OF MEXICO, STILL LOOKING AT WINDS 110 MILES PER HOUR. THAT'S A REALLY STRONG CATEGORY 2 STORM. THERE IT GOES ACROSS THE GULF, AND NOTICE HOW IT RESTRENGTHENS TO A CATEGORY 1 STORM. LANDFALL WILL BE SOMEWHERE IN NORTHEASTERN MEXICO, SOUTHERN TEXAS THAT WILL YET TO BE DETERMINED OVER THE NEXT FEW DAYS. HOT IN THE TROPICS. HOT ACROSS THE U.S. TOO. WE'RE LOOKING AT 148 MILLION PEOPLE UNDER HEAT ALERTS ACROSS THE WEST. THIS IS GOING TO BE DAYS AND DAYS, INTO NEXT TUESDAY AT LEAST. WE'RE LOOKING AT THE HEAT AND HUMIDITY INTO THE SOUTHWESTERN STATES. TEMPERATURES INTO THE TRIPLE-DIGITS IN MANY SPOTS. HALLIE? >> MICHELLE, THANK YOU. >>> AS AMERICANS CELEBRATE THE FOURTH OF JULY, LAW ENFORCEMENT IS ON HIGH ALERT ACROSS THE COUNTRY. EMILIE IKEDA IS JOINING US NOW. EMILIE, POLICE ARE DEPLOYING MORE RESOURCES THAN EVER BEFORE ON THIS HOLIDAY, RIGHT? >> HALLIE, THAT'S RIGHT. POLICE BEEFING UP SECURITY ON BOTH SIDES OF THE HUDSON RIVER HERE, WITH FIREWORKS SET TO LAUNCH FROM BARGES. FEDERAL AUTHORITIES SAY THERE IS NO CREDIBLE THREAT THIS JULY 4th, BUT LAW ENFORCEMENT OFFICIALS WE'RE HEARING FROM ACROSS THE COUNTRY SAY THEY'RE ON LIE HAWAII ALERT. AN INTELLIGENCE BULLETIN NOTES A CONCERN IS A LONE WOLF TRYING TO PROMOTE SOME KIND OF AGENDA. WE KNOW THE NYPD IS ROLLING OUT DRONES, DOGS, THOUSANDS OF OFFICERS, EVEN THERMAL TECHNOLOGY. THE POLICE DEPARTMENT ACKNOWLEDGES THE COMPLICATED THREAT ENVIRONMENT IN LIGHT OF WARS RAGING ABROAD AND POLITICAL TENSIONS HERE IN THE U.S. MEANTIME, THOUSANDS OF SPECTATORS HAVE ALREADY STARTED TO GATHER FOR THE NATION'S LARGEST FIREWORKS DISPLAY, HALLIE, SET TO RUN FOR 25 MINUTES. >> EMILIE IKEDA, THANK YOU. >>> OVERSEAS NOW, IN WHAT APPEARS TO BE A MAJOR SHIFT IN THE UK TONIGHT AFTER CRITICAL ELECTIONS. RAF SANCHEZ IS AT 10 DOWNING STREET. IN LONDON. RAF, IT LOOKS LIKE THERE MAY BE A NEW PRIME MINISTER SEASON? >> THAT'S RIGHT, HALLIE. EXIT POLLS RELEASED LAST HOUR PROJECT THE RULING CONSERVATIVE PARTY WHICH HAS BEEN IN POWER FOR 14 YEARS IS HEADING FOR A HISTORIC DEFEAT WHILE THE OPPOSITION LABOUR PARTY WILL WIN A LANDSLIDE VICTORY. AND ITS LEADER, KEIR STARMER WILL BECOME BRITAIN'S NEW PRIME MINISTER. STARMER IS A CHAMPION OF NATO AND OF UKRAINE, FOREIGN POLICY VIEWS THAT CLOSELY ALIGN WITH PRESIDENT BIDEN, BUT COULD BE AT ODDS WITH DONALD TRUMP. AND IF STARMER WINS TOMORROW, HE WILL HEAD TO BUCKINGHAM PALACE TO MEET KING CHARLES BEFORE WALKING THROUGH THAT FAMOUS BLACK DOOR OF DOWNING STREET FOR THE FIRST TIME AS THE UK'S NEW LEADER. HALLIE? >> RAF SANCHEZ LIVE IN LONDON, THANK YOU. >>> IN THE MIDDLE EAST, A PHONE CALL TODAY BETWEEN ISRAEL'S PRIME MINISTER AND PRESIDENT BIDEN AND SOME MOVEMENT REPORTED ON NEGOTIATING A RELEASE OF THE HOSTAGES IN GAZA. HERE IS MATT BRADLEY. >> Reporter: TONIGHT, ISRAEL'S PRIME MINISTER TELLING PRESIDENT BIDEN THAT ISRAEL WILL SEND NEGOTIATORS TO ANOTHER ROUND OF CEASEFIRE TALKS AND NOW STUDYING A HAMAS RESPONSE TO ITS PROPOSAL. HAMAS STILL HOLDS THE POWER IN GAZA, BUT OUR NBC NEWS TEAM THERE DISCOVERING GROWING SIGNS IT'S LOSING PUBLIC SUPPORT. THIS WOMAN HAS JUST SEEN THE BODY OF HER SLAIN SON. HE WAS KILLED BY AN ISRAELI BOMBARDMENT, BUT SHE DIRECTS HER ANGER AT HAMAS WHOSE OCTOBER 7th ATTACKS SPARKED THE ISRAELI INVASION. "I HOPE THAT GOD WILL DESTROY YOU, HAMAS, LIKE YOU DESTROYED OUR CHILDREN," SHE YELLS. THIS KIND OF DISSENT AGAINST HAMAS' RULE WAS ONCE RARE IN GAZA AND IT'S STILL RISKY. BUT AS ISRAEL'S WAR ENTERS ITS TENTH MONTH, FRUSTRATION IS OVERFLOWING. THIS MAN SPEAKS TO A STUNNED CROWD IN FRONT OF A HOSPITAL. "WE HAVE A FILTHY LEADERSHIP. THEY GOT USED TO OUR BLOODSHED," HE SAYS. THIS MAN REGULARLY CONDUCTS POLLS THROUGHOUT THE PALESTINIAN TERRITORIES. >> THE HAMAS POPULARITY AMONG THE POPULACE WHO ARE LIVING NOW IN SHELTERS AND TENTS AND MAKESHIFT, YOU KNOW, COMMUNITIES IS DECLINING. >> Reporter: FOR MANY HERE, THIS IS HAMAS' WAR, AND THEY'RE SACRIFICING GAZAN CIVILIANS. THIS OPPOSITION ACTIVIST SAYS "WE REFUSE TO CONTINUE THE WAR OVER OUR KIDS' AND WOMEN'S BODIES AND BLOOD." AND TONIGHT A SENIOR U.S. OFFICIAL TOLD NBC NEWS THAT ISRAEL'S BORDER OPERATION IN RAFAH HAS PUT REAL PRESSURE ON HAMAS, AND NOW BOTH HAMAS AND ISRAEL WANT A DEAL. HALLIE? >> MATT BRADLEY, THANK YOU. >>> WHEN WE COME BACK, THE FBI INVESTIGATING CHINESE SWIMMERS WHO TESTED POSITIVE FOR DOPING AFTER THE TOKYO OLYMPICS FOUR YEARS >>> WE'RE LEARNING OF TWO SHARK ATTACKS ON BEACHES IN FLORIDA AND TEXAS THIS HOLIDAY WEEKEND. OFFICIALS ON SOUTH PADRE ISLAND SAY A MAN WAS BADLY HURT WHEN HE WAS BITTEN BY A SHARK ON HIS LEG. ANOTHER BEACH THERE APPARENTLY HAD A MORE MINOR SHARK BITE. AND LATE TODAY, OFFICIALS IN NEW SMYRNA BEACH, FLORIDA SAY A 21-YEAR-OLD MAN WAS BITTEN ON THE FOOT WHILE PLAYING IN KNEE-DEEP WATER. >>> AND WE'RE LEARNING TONIGHT THE U.S. IS NOW INVESTIGATING CHINESE SWIMMERS WHO TESTED POSITIVE FOR DOPING AFTER THE TOKYO OLYMPICS FOUR YEARS AGO, AND WHO ARE SET TO COMPETE AT THE PARIS GAMES IN JUST A FEW WEEKS. DAVID NORIEGA IS FOLLOWING IT ALL. AND DAVID, THE FBI SNOW LOOKING INTO THIS? >> Reporter: THAT'S RIGHT, HALLIE. 11 SWIMMERS, SO ABOUT A THIRD OF THE CHINESE OLYMPIC SWIM TEAM TESTED POSITIVE FOR PERFORMANCE-ENHANCING DRUG IN THE CONTEXT OF THE LAST OLYMPICS, BUT THEY NEVER FACED ANY CONSEQUENCES, AND THEY'RE STILL COMPETING AGAIN THIS YEAR. THAT'S BECAUSE WORLD ANTI-DOPING AUTHORITIES CLEARED THEM ON THE GROUNDS THEY HAD ALL BEEN ACCIDENTALLY CONTAMINATED. BUT MANY SUSPECT A COVER-UP. CHINA DENIES THERE WAS ANY DOPING OR A COVER-UP FOR THAT MATTER, BUT THE FBI IS LOOKING INTO THE CASE, USING A CONTROVERSIAL LAW PASSED IN 2020 THAT ALLOWS U.S. AUTHORITIES TO INVESTIGATE INTERNATIONAL DOPING SCHEMES EVEN IF THEY DON'T DIRECTLY INVOLVE AMERICAN ATHLETES. THE SCANDAL COULD CAST A DARK CLOUD OVER THIS YEAR'S SWIMMING EVENTS WITH JUST THREE WEEKS LEFT UNTIL PARIS. HALLIE? >> DAVID NORIEGA, THANK YOU. >>> COMING UP HERE ON THE SHOW, HOW YOU CAN SCORE BIG ON HOLIDAY >>> THIS FOURTH OF >>> THIS FOURTH OF JULY A SHOPPING HOLIDAY FOR MANY. RETAILERS ARE TRYING BIG SALES. TO REEL FOLKS IN. BRIAN CHEUNG HAS MORE ON HOW TO SCORE. >> Reporter: SHOPPERS ON THE HUNT FOR A DEAL, HOPING FOR A STEAL IN FOURTH OF JULY SALES, AS AMERICAN CONSUMERS SHOW SIGNS OF CAUTION. >> WHAT I'M SEEING REALLY WITH CONSUMERS IS THAT THEY ARE PULLING BACK A LITTLE BIT. THEY'RE BEING MORE CONSERVATIVE. >> Reporter: CONSUMER SENTIMENT OVER THE ECONOMY HAS DECLINED FOR THREE STRAIGHT MONTHS. BUT WITH WAGE GROWTH OUTPACING INFLATION, SIGNS THAT AMERICANS MIGHT STILL BE WILLING TO AT LEAST TAKE A LOOK AT SALES. RETAILERS ARE ADVERTISING DISCOUNTS TO HELP SHOPPERS INDULGE IN A LITTLE OUTDOOR FUN. SWIMWEAR 30 TO 40% OFF. TENTS 50 TO 60% OFF, AND BIG TICKET ITEMS LIKE PATIO FURNITURE SETS UP TO 55% OFF. BUT FOR OTHER ITEMS, EXPERTS SAY WAIT. >> I WOULD REALLY PASS ON TECH RIGHT NOW, AND I WOULD ALSO PASS ON BACK TO SCHOOL. YOU MAY SEE A DEAL HERE AND THERE FOR BACK TO SCHOOL. BUT REALLY, THE BEST BACK TO SCHOOL DEALS WILL BE KICKING IN WITH THE BIGGER SALES A LITTLE LATER IN JULY. >> Reporter: THOSE DEALS LIKELY TO COME FROM SALES AT TARGET AND WALMART, SLATED TO KICK OFF NEXT WEEK, AS WELL AS AMAZON'S PRIME DAY SET FOR JULY 16 AND 17. IF YOU CAN WAIT EVEN LONGER, EXPERTS SAY THE BEST DISCOUNTS ON SUMMER WEAR AND GOODS WILL BE AT THE END OF THE SEASON. AND FOR ELECTRONICS, THE SWEET SPOT IS BLACK FRIDAY AND CYBER MONDAY. BUT ALWAYS MAKE SURE YOU'RE TRULY GETTING THE BEST DEALS. HOW DO YOU MAKE SURE YOU'RE GETTING THE BEST DEAL? >> I LIKE TO USE YAHOO SHOPPING OR GOOGLE SHOPPING. ENTER THE NAME AND YOU'LL SEE ALL THE AVAILABLE DEALS AND PRICES IN ONE PLACE. >> Reporter: GOOD ADVICE FOR THOSE DIVING INTO SUMMER SAVINGS. BRIAN CHEUNG, NBC NEWS, NEW YORK. >>> COMING UP, HOW DO THEY GET READY FOR ONE >>> FINALLY, IT'S ONE OF THE COUNTRY'S FOURTH OF JULY SPECTACLES. AND OUR KAYLEE HARTUNG IS GETTING A BEHIND-THE-SCENES LOOK BEFORE THE MACY'S FIREWORKS SHOW TONIGHT. >> Reporter: HERE IN THE MIDDLE OF THE CALIFORNIA DESERT -- >> THREE, TWO, ONE, FIRE! >> Reporter: THE SOUZA SOME OF THE NEWEST, MOST HIGH-TECH FIREWORKS IN THE WORLD. >> OH, WOW! >> Reporter: PREPARING FOR THEIR BIGGEST SHOW OF THE YEAR, THE ICONIC MACY'S FOURTH OF JULY FIREWORKS SHOW. HOW COMPLICATED IS IT TO PRODUCE SOMETHING OF THE MAGNITUDE OF THE MACY'S FOURTH OF JULY SHOW? >> I THINK THAT ONE OF THE THEMES THAT WE SAY IS BIGGER AND BETTER THAN EVER. AND I THINK IT PUSHES US, AND IT PUSHES US TO SEARCH THE WORLD TO FIND THE BEST FIREWORKS. >> Reporter: BROTHERS JIM AND GARY SOUZA ONE RUN PYRO SPECTACULARS BY SOUZA. >> IT STARTED OVER 100 YEARS AGO WITH OUR GREAT GRANDFATHER. >> ONCE YOU SMELL THE POWDER, AND YOU GET THE POWDER IN YOUR BLOOD, YOU NEVER LEAVE. >> Reporter: IS THIS TABLE TALK AT YOUR FAMILY? >> WELL, YOU KNOW, IT ALWAYS HAS BEEN, YEAH. >> Reporter: MORE THAN 60,000 MORTAR SHELLS WILL BE LAUNCHED FROM FIVE BARGES ACROSS THE HUDSON RIVER THIS YEAR. WILL WE SEE BIGGER AND BETTER THIS YEAR? >> WE HAVE SOME NEW SURPRISES. >> OH, WOW! >> Reporter: WE GOT A SNEAK PEEK AT THEIR DESERT TESTING SITE. SOUZA STANDARD? >> YEAH, THAT'S IT. >> Reporter: SHOWCASING FIREWORKS THAT EXPLODE INTO AN INCREDIBLE EIGHT DIFFERENT COLORS. >> OH, BEAUTIFUL! >> Reporter: AND DRONES WITH THEIR OWN FIREWORKS ATTACHED. >> THAT WILL BE THE VERY FIRST TIME THAT'S EVER HAPPENED IN THE UNITED STATES. >> Reporter: EACH FIREWORK IS HAND-MADE. THESE COLORFUL BALLS OF POWDER STRATEGICALLY PLACED INSIDE THE SHELL TO EXPLODE IN A MAGICAL DISPLAY. THIS IS A MOCK-UP OF ONE OF THE SHELLS WE'LL SEE GO OFF TONIGHT. >> THIS WILL MAKE A DOUBLE CROSSING RING WITH RED STARS. >> ENCORE! >> WHEN YOU HEAR THE CROWD ROAR, YOU KNOW YOU DID IT. AND THAT PROVIDES THE INSPIRATION FOR NEXT YEAR. >> Reporter: KAYLEE HARTUNG, NBC NEWS. >> QUITE A SHOW. THAT'S "NIGHTLY NEWS" FOR THIS THURSDAY. FOR ALL OF US HERE AT NBC, I'M HALLIE JACKSON. THANKS FOR WATCHING, AND HAVE A GREAT HOLIDAY WEEK. HAVE A GREAT HOLIDAY WEEK.