It involved a small truck with a Papa John's sign on the top. The truck had a sofa and other items in the back.
Raleigh police say they believe 36-year-old Zaixin Chen was standing in the bed of the truck, when the driver apparently hit a bump in the road, causing him to fall off.
"It is believed that a gust of wind may have gotten under the mattress the victim was attempting to hold in the bed of the truck, lifting the mattress and ejecting the victim," Raleigh Police Department Public Information Officer Jim Sughrue said.
Officials say Chen fell from the back of the truck and was taken to Wake Med in critical condition.
"They say he was barely moving, so I guess it was pretty bad," eyewitness Kaliyah Suggs said.
Suggs says she saw Chen moments before he fell. He seemed to be holding down a mattress -- a task Suggs says was not easy to do because of the wind.
"It was just sliding off and as it was sliding off, I guess he was just trying to hold it back and keep it in the truck, but as the mattress had rolled off, he went with it," Suggs said.
Police say the driver of the pick-up truck, Arlene Cates, did not realize Chen had fallen off the truck, so she initially kept driving. She eventually turned around and returned to find Chen in the middle of Lynn Road.
Cates was arrested at the scene under suspicion of driving while impaired. She is facing several charges including DWI and a felony for causing a serious injury with a motor vehicle.