CHICAGO (CBS) — One person was killed and five others were wounded in a shooting at a public housing complex in the Little Village neighborhood, including a teenager first presumed dead and covered in a sheet before police and paramedics realized he was still alive.

Police said the shooting happened around 4:45 a.m. at the ABLA Brooks Homes public housing complex near 13th and Loomis.

Police First Deputy Supt. Anthony Riccio said none of the surviving victims were cooperating with police, but evidence at the scene suggested there was an exchange of gunfire between several people. Riccio said there is an ongoing gang conflict in that area, and the shooting appeared to stem from some sort of dispute.

“This is a tragedy, and we are working through profiles and backgrounds to get an idea as to what could have prompted the shooting,” he said.

At least four of the victims were previously known to police.

Police originally said two people were killed in the shooting, but later clarified one person had been killed and one was in very critical condition.

A 23-year-old woman was found dead about a block away from the shooting, near Washburne and Loomis. She had suffered gunshot wounds to the chest, arm, head, and ear, and was pronounced dead at the scene.

Riccio confirmed paramedics initially presumed a 17-year-old boy who had been shot several times in the head had died, and covered him in a white sheet.

“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,” Riccio said.

Later, police officers noticed movement under the sheet.

“Officers who were present notified the paramedics this man is still alive, and treatment began on him as well,” Riccio said.

The 17-year-old was taken to Stroger Hosptial in critical condition. Riccio said he was on full life support, and his family was deciding how to proceed.

“That individual has a catastrophic injury. He was shot in the head, and the prognosis is not good,” he said.

Riccio said he did not know how long the teen lay under the sheet before paramedics began CPR.

“That is something that I think definitely has to be looked at to find out exactly why that happened,” he said.

Four other people were wounded in the shooting.

A 21-year-old man who was shot in the right calf was taken to Stroger Hospital, where his condition was stabilized. A 23-year-old man who was shot in the right arm also was taken to Stroger Hospital, where his condition was stabilized. A 23-year-old man who was shot in the abdomen was taken to Mount Sinai Hospital, where his condition was stabilized. A 21-year-old man who was shot in the left leg was treated and released at Rush University Medical Center.

Police said a weapon, possibly a MAC-10 submachine gun, was recovered near the body of the 17-year-old boy.

Detectives also were reviewing video from several cameras in the area.

Area Central detectives were investigating.