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Just when Egyptian tourist Nader El Shafei looked like he might fall next under its large wheels, the truck stopped.

The crime scene, along the city's waterfront, was eerily quiet today, as investigators and forensics teams searched for evidence. "All these bodies and their families. they spent hours on the ground holding the cold hands of bodies dismembered by the truck".

Throughout the day, onlookers visited the site, many still in shock.

A nine-year-old and his family "have finally been found!" one recent post crowed atop a photo of a child in front of a birthday cake. I don't feel safe.

There are new details about what happened Thursday night in Nice, France, when a man drove a truck through a crowd.

Athens City Hall is illuminated in the colors of the French national flag in memory of the victims of the Nice attack and in solidarity with the French people in Athens, Greece on July 15, 2016. In France, that's essentially their version of July 4. "There are many children, he said". The driver continued forward as he hit scores of people.

MELISSA CHARLET, Eyewitness: It was awful. "It is all of France that is under the threat of Islamist terrorism". "I saw people being knocked over like skittles", said Gordon, who had just left the promenade with his wife and 18-month-old daughter. Most of the people were on the phone, calling their friends, "Where are you? I have lost you".

Stephane Erbs said he was heading back to his vehicle with his wife, Rachel, and their two children when he saw the truck bearing down on them. And it was really scary.

French President Francois Hollande said dozens of people are in critical condition.

JANE FERGUSON: This afternoon, the truck was hauled away from the scene.

Hours before the carnage unfolded in Nice, President Francois Hollande told Bastille Day revellers in Paris that "we can not prolong the state of emergency eternally" and indicated that it would soon be lifted. Overnight in Nice, we witnessed another tragic and appalling attack on the freedom and the peace that we cherish.

French President Francois Hollande, after visiting a hospital where some of the victims are being treated, called the attack "unspeakable".

USA government agencies have received constant reports of Islamic State threats to attack France and those threats are regarded as current, a US security official said.

Condolences also poured in from other capitals. The burgeoning ranks of his political opponents already are saying that any president who has allowed three of the nation's deadliest terrorist attacks is failing on security.

In times like these it's often easier to see what we shouldn't do than what we should, because there inevitably will be voices counseling us to embrace our fears and act on them. And this is a threat to all of us.

She went downstairs and crossed the street, where "there were many, many bodies and we knew they were dead because they were covered with sheets".

France will begin a three-day period of mourning on Saturday. He was handed in March a suspended six-month sentence for a violent confrontation in January, but was "totally unknown" to national intelligence services and was not known to have been radicalised. Now, it's not clear yet whether or not this attack was in fact linked to radical Islam.

French authorities said Friday that the attack launched in Nice during France's national celebrations for Bastille Day was like those provoked by jihadist groups worldwide, though none has yet claimed responsibility for the bloodshed. "I saw some terrible things". People have been lighting candles and leaving mementos here.

Attackers with assault rifles and explosives, pledging allegiance to an Islamic terror group, killed 89 people at a concert in November.