A woman is dead after a hit-and-run in Brooklyn involving a tractor trailer carrying cars.

Police say it happened as the victim was crossing Caton Avenue near St. Paul's Place in Flatbush around 8:30 p.m. Wednesday.

They say they later tracked down the driver, and that he may not have known he hit her.  

Witnesses say it was a gruesome scene.

"We were driving, and then we saw that the truck hit her, and she just laid right on the floor. The truck just left," said one witness. "I don't know if he seen her or not, but she just lay on the floor, body dismembered."

Police say the victim was in her 40s. 

The investigation is ongoing.