Police say that an attempted sneaker robbery in Brooklyn yesterday resulted in a teen being run over by an SUV and having his arm ripped off.

This incident unfolded around 1 p.m. on Friday on E. 86th Street near Avenue M in Canarsie when 17-year-old Zachary Sam met with 39-year-old Phillippe Pierre so the younger man could buy a pair of Air Jordans off of him. When Pierre, a married father of three, asked for $190 for the Air Jordan 8 Retro sneakers, Sam allegedly pulled a gun on him inside Pierre's SUV and demanded the shoes for free.

As you can see in the (very ominous) surveillance video below, via ABC, Sam took the shoes and exited the car. Pierre sped down the block, made a U-turn, then slammed into the teen, pinning him against a metal fence.

Surveillance video shows teen robbery suspect being run down b... Exclusive surveillance video shows a teen suspect being run down by the victim he allegedly robbed at gunpoint in Brooklyn. (Warning: Video may be considered disturbing) Details: http://7ny.tv/1SmvHk4 Posted by ABC7NY on Friday, February 12, 2016

The impact of the SUV apparently sheared off Sam’s right arm just below the elbow. "I saw a kid under a car," witness Alex Saint Fleur, a bus driver who lives across the street, told the Post. "The guy ran him over. He got out, the driver said, 'He’s trying to rob me. He’s trying to rob me.'" Fleur says he saw the gun on the ground: "The arm was on the floor near the gun." Then Sam ran onto a city bus: "Everyone is screaming, 'Come back, come back, your arm. You’re bleeding too much,'" Fleur added.

Sam got off the bus and eventually collapsed in the middle of Avenue M; he was taken to Bellevue Hospital, where doctors spent hours trying to reattach his arm. He remains in serious but stable condition, and it is unclear whether doctors will be able to save the arm.

Sam has been charged with robbery and criminal possession of a weapon, while Pierre has also been arrested and charged with attempted murder. "Two families are destroyed tonight—my cousin, and this kid's family," Pierre's cousin, Michael, told ABC. "I know what the video's showing—if somebody pulls a gun in your head, and you're trying to get the cops to catch him, what would you do? You're telling me just let him go?"