Video of the incident, which took place near North Broadway and O’Fallon Street at around 2:19am on Saturday, shows several protesters approach the large, white truck.
The driver of the truck was forced to take a detour after protests shut down Interstate 70, according to the findings of a preliminary investigation by the St. Louis Metropolitan Police Department, the Daily Mail reported.
He then started driving down North Broadway toward Cass Avenue until he was forced to stop due to the presence of a large group of people.
While he was stopped, several individuals began taking packages and data-x-items from his truck.
According to the police, two men stood on the passenger side footboard and showed the driver they had guns.
In video posted to social media, several witnesses also reported seeing men with guns near the truck.
Investigators said the driver of the tractor-trailer was not aware that a man was caught on the converter dolly between the two trailers.
He told police that he feared for his life and honked the horn, according to KSDK-TV. He then kept on driving until he was stopped by police.
FedEx released a statement saying: ‘Our hearts go out to all those who are grieving the events of this week.
‘We are deeply saddened to learn of a tragic situation involving a demonstrator in St. Louis and one of our vehicles.
‘We offer our sincerest condolences to the family of the individual involved.
‘There is no higher priority for FedEx than safety, and we are cooperating fully with the investigating authorities at this time.’
The crowd dispersed after a few gunshots were fired. Police did not report any arrests.
Floyd’s death has sparked protests across the United States and fires and violent unrest in Minneapolis.
Tensions between police and minority residents have lingered in the St. Louis area since the 2014 death of Michael Brown in Ferguson.