A 71-year-old man died after he struck and killed by a tractor-trailer that was backing up in southeast Arlington Wednesday morning.

The man was standing behind the cab of a commercial tractor-trailer truck in an industrial area in the 4000 block of New York Avenue at about 10:30 a.m. when the driver of the truck, unaware that the man was standing behind him, backed up the cab to connect to a trailer, striking him, according to a news release from the Arlington Police Department.

He was driven by ambulance to the Medical Center of Arlington where he later died, police said.

It appears that the man was doing something with the trailer’s hitch when the driver backed up and struck him, Arlington police spokeswoman Tiara Richard said.

It’s not known if the two men worked at the same business but it appeared that they were working together and knew each other, Richard said.

The man has not been named at this time as officials are in the process of notifying his family, the release stated.

This is the 11th traffic fatality in Arlington this year and the second one involving a pedestrian being struck and killed after 15-year-old Jennifer Herring was struck and killed April 18by a vehicle in south Arlington.

Ten days earlier, 7-year-old Frida Flores was struck and killed while riding her bike at a north Arlington apartment complex.

Flores’ death did not take place on a city street so it was not officially counted as a traffic fatality but that doesn’t change how the case was investigated, Richard said.