A truck plowed into pedestrians during Bastille Day celebrations in the popular French seaside city of Nice on Thursday night.
What we know:
- French officials say 84 people are dead and 202 people were injured.
- The mayor of Nice's office identified the attacker as Mohamed Lahouaiej Bouhlel, a 31-year-old Tunisian-born émigré living in France. He was killed by police at the scene.
- French prosecutors said the suspect was not known by local or national intelligence services and he was not on a terrorist watch list.
- French President Francois Hollande extended a nationwide state of emergency three months.
- An American father and his 11-year-old son have been confirmed among the dead.
Sylvain Benouaich, a 52-year-old maintenance worker, said he was sitting at a sports bar along a busy Nice promenade when a driver entered an area blocked off to vehicles.
The night of revelry quickly descended into chaos.
"I look at the truck and I don't understand why he is inside of the zone, inside the place when nobody can drive," Benouaich said. "And I hear a lot of people cry and the noise, it's very important, you know, help, the people panic, big panic. They run to the left and ... to the right, nobody knows where to go."
He pulled out his cellphone and began to record what ended up being the last few seconds of the confrontation between police and the driver, later identified as 31-year-old Mohamed Lahouaiej Bouhlel.
Benouaich described seeing police take two men into custody outside the truck near its rear-end as they confronted and killed Bouhlel. He doesn't know if the men were officially arrested or involved in the attack.
"In this video, you can see policemen shoot the terrorist and (make) an arrest," Benouaich said. "They stop two men near the truck and immediately take the men and ... put them in a police car."
Paris prosecutors updated the injury count and the conditions of victims during a news conference Friday afternoon. Here is the latest numbers:
202: Total people wounded.
52: The wounded still in critical condition.
25: The wounded who are also on life support.
84: Total people killed.
10: Those killed who were children/teenagers.
An amber-alert-style app that is supposed to warn citizens of a major crisis failed to work during the Nice truck attack, it was reported.
The geolocation-based SAIP application was supposed to flash a red warning screen but Twitter users in Nice said the alert wasn't received until three hours after the massacre began.
The company that developed the app was summoned to the French Interior Ministry in Paris on Friday, Le Figaro reported.
The system was designed after the November 2015 attacks in Paris and launch in June, two days before the start of the Euro 2016 soccer tournament.
Users who receive a red warning triangle must press their smartphone screen to cancel the warning, an action that triggers another page with incident-specific advice on how to remain safe, the newspaper said.
Twitter users complained that the delayed alert was an "incredible failure."
"This app had one job, and it didn't even do that," wrote Nathan Lellouche, from Nice, who posted a screenshot of the app, taken after the attack, showing a green 'all clear' message.
A woman who said she is the neighbor of Nice attack suspect described him Friday as a frightening man and "not normal."
Officials say Mohamed Lahouaiej Bouhlel, a 31-year-old Tunisian-born Frenchman, drove a truck into crowds celebrating Bastille Day, killing dozens of people.
A woman called Hanan, who told Reuters she lives in the building believed to be the one inhabited by Bouhlel, said he was odd.
"He looked at us weirdly, he wouldn't even open the door, when we'd arrive behind he'd slam the door shut. Frankly, not normal," she said.
She described him as "a handsome man, going gray, in his 30s ... I would say he was someone who was pleasing to women."
Hanan said he was "always alone."
She added: "He didn't have a frightening face, but ... a look, a look. He would stare at the children a lot."
Forensic police searched an apartment on the first floor in the building, which is in a relatively poor neighborhood to the east of downtown Nice.
A controlled explosion was carried out on an abandoned package in the district where the Nice truck attack suspect lived, local media reported.
Bomb disposal experts were at the scene in the Route de Turin district in the east of the city, according to Le Figaro and Nice Matin.
A Volvo rental truck and a nearby apartment were searched and two nearby buildings were evacuated, Nice Matin said.
Fatima Charrihi, one of the victims of the attack, was an amazing mom and a devoted Muslim, her tearful son told a French newspaper Friday.
In an interview with L'Express, the son, identified as Hamza, said his mom was the first victim of the truck attack. "There weren't any other bodies in front of her," he said.
The mother of seven was with her nieces and nephews when the attack happened.
"She was an amazing mother," Hamza said, speaking outside the local university that had been turned into a waiting area for victims' families. "She wore the veil, she practiced real Islam — not like those terrorists."
A total of 50 truck attack victims were critically injured and "between life and death," France's president told reporters Friday after visiting some of the survivors at a hospital.
Francois Hollande praised medics who rushed to work "in the middle of the night to save lives" following the Bastille Day atrocity. He described police, firefighters and other public workers who responded as "the pride of France."
The country was "facing a long battle," Hollande warned, saying the attack was intended "to satisfy the cruelty of an individual, and maybe a group."
Addressing a country seeking answers, he said: "Why Nice? Because it is known all over the world, it is one of the most beautiful cities in the world. Why July 14? Because it is a celebration of liberty."
However, he insisted that France must be strong.
"The world is watching us," Hollande added.
The outspoken leader of France's far-right National Front party said the country must declare "war against the scourge of Islamic fundamentalism."
In a statement following Thursday's deadly truck attack in Nice, Marine Le Pen called on France to implement the "necessary measures of prevention and suppression" of Muslim hardliners.
Le Pen has been pushing for tighter immigration laws in France and a crack down on Islamists in the wake of recent terror attacks.
The truck driver has been identified as Mohamed Lagouaiej Bouhlel. While French media reported that ID papers belonging to a French-Tunisian were found in the truck, no terror group has claimed responsibility for the rampage and a motive remains unclear.
Le Pen also expressed condolences for the victims, adding that the festive Bastille Day events were instead turned into "a horror day of great sorrow."
The Associated Press is reporting that passengers are being allowed back into Nice Airport.
An NBC News journalist who had just landed earlier said people were again being allowed through immigration after a 30-minute wait.
It wasn't immediately clear what caused the scare.
French President Francois Hollande flew to Nice on Friday, where he and Prime Minister Manuel Valls met with local officials.
They later visited one of the hospitals where victims of the attack were taken, meeting the wounded and offering support to medical personnel.
An Interpol team is being deployed to Nice to assist with the investigation into the attack, the agency said Friday.
The officials include victim identification experts along with terrorism and information specialists who can carry out real-time checks on the agency's databases, according to Interpol.
It announced the news in a statement condemning the attack and offering full support to French authorities.
"On behalf of the world police community, Interpol condemns this cowardly and horrific attack in the strongest terms," Interpol's Jürgen Stock said in a statement. "We remain in full solidarity with the citizens of our host nation, France and are providing all support necessary to French authorities."
Nice Airport was partially evacuated Friday and bomb squads called in after a suspicious package was reported in the arrivals lounge of Terminal 1, officials said.
An NBC News journalist who had just landed at the airport said he was held up at immigration for 30 minutes before passengers started being let through.
Vehicle-borne improvised explosive devices are a well-established threat in Afghanistan and Iraq where motorcycles and pick-ups laden with explosives are driven towards security checkpoints or convoys of soldiers.
But the massacre of families enjoying a national celebration in France underscores fears that the use of vehicles as weapons in themselves is a growing threat in the United States and other Western countries.
U.N. Secretary-General Ban Ki-moon joined the outpouring of condolences on Friday, condemning the "horrific" attack and expressing sympathy for the victims.
"The secretary-general hopes that all those responsible for this massacre will be rapidly identified and brought to justice," his office said in a statement. "He stands firmly by the French government and people as they confront this threat and stresses the need to intensify regional and international efforts to combat terrorism and violent extremism."
New British Prime Minister Theresa May said she was "shocked and saddened by the horrifying attack" in Nice.
Speaking on only her third day in office, she mourned the loss of "innocent victims enjoying a national celebration with their friends and families."
Supreme Court Justice Clarence Thomas left Nice just hours before the attack, according to a California law school.
He was teaching a study abroad course in the French city through the San Diego-based Thomas Jefferson School of Law, a spokesman told NBC San Diego.
Thomas, 68, agreed to teach the course after the death of Supreme Court Justice Antonin Scalia, who had been scheduled to participate in the program for the fifth time, the school said.
"Justice Scalia would be proud to have Justice Thomas teach Constitutional Law in his place, a subject about which the late Justice Scalia was passionate," Thomas Guernsey, president and dean of Thomas Jefferson School of Law, said in a statement in March.
Pop star Rihanna canceled her concert in Nice following the deadly attack in the French city.
The singer posted a message on her Instagram account saying that her show scheduled for Friday at the Allianz Stadium would not go on as planned.
The tragedy also prompted the cancellation of the Nice Jazz Festival, which was due to start Saturday.
"The city of Nice is in mourning," the festival's Twitter account said in a message. "Our thoughts are with the victims."
London Mayor Sadiq Khan said he would review security in the city of more than 8 million in the wake of the deadly truck attack in the French city of Nice.
"I want to reassure all Londoners that today we will be reviewing our own safety measures in light of this attack and that I and the Metropolitan Police commissioner will do everything possible to keep London safe," he said in a statement Friday.
He also pledged to "stand united with Nice and all of France in our grief."
Khan added: "We are also united in our determination to root out and defeat the sick and evil individuals who have tried to divide us with this cowardly act of terror."
A series of bombings on public transportation killed 52 people in the U.K. capital on July 7, 2005.