Jacob Stevens had been manning the bounce house at Cornerstone Assembly church’s Trunks of Treats event on Halloween night, waiting for his turn to use the pumpkin launcher. The 16-year-old got down on his knees to use the device, which is similar to a slingshot. “When he let it go, the pumpkin didn’t release and it just recoiled back and hit him in his chest,” his mother Jan Stevens said.