First responders had already draped a sheet over a 17-year-old who was shot in the head and left for dead.
But after a few minutes went by, the unidentified teen restarted breathing.
They quickly lifted the sheet and worked to revive him by performing chest compressions, police said. He was then rushed to Stroger Hospital, where he was listed in very critical condition.
"I do understand that paramedics looked at him, believed him to be deceased, covered him with that sheet and moved on to another individual who was nearby who was also shot. They saw motion, movement underneath the sheet," Chicago Police First Deputy Superintendent Anthony Riccio told reporters, according to ABC station WLS. Officers who were present notified paramedics, this man is still alive."
"That individual has a catastrophic injury," Riccio added. "He was shot in the head, and the prognosis is not good."
The 17-year-old was one of five victims from a drive-by shooting early Monday in Chicago.
A 23-year-old woman shot in the chest, left arm, head and ear a block away from where the boy was found was pronounced dead at the scene, police said.
Everyone shot was attacked as a house party on South Loomis Street near west 13th Street started clearing out around 4:45 a.m. Then, police said, a pair of cars were spotted roaming around the party and somebody drew a weapon and started firing off gunshots.
The other gunshot victims were four men in their 20s, all of whom are expected to survive, police said.