From TIME:

A large truck plowed into a crowd of people in the southern French of city of Nice on Thursday night, killing at more 70 people and injuring at least another 100 as the heavy vehicle mowed over its victims along hundreds of feet, according to police and government officials. The grim death toll jolted the entire country, which has been tenterhooks for months, wondering if and when another deadly assault might occur.

The incident occurred just as thousands of people poured on to the streets on a warm midsummer’s night to celebrate the country’s biggest public holiday of the year, Bastille Day, and to watch the fireworks display — a traditional feature in every city and village across France in the annual celebrations. The truck slammed into the crowds gathered on the city’s Promenade des Anglais, which runs along the Mediterranean seafront, and sent those who could escape screaming in panic as they fled the scene.

Eye-witnesses reported seeing the driver exit the truck and fire a gun into the crowd. He was later killed by police, TIME reports.

According to CNN, French officials told newscasters that 73 people have been killed.

Maryam Violet, a witness, said she was walking along the beach and saw "a ton of people on the ground and on the sidewalk." "You could see someone with a bike or a wheelchair and someone with a bag full of flowers, innocent and normal people on the beach."