Duncan Price's family became concerned after he did not return home from dialysis at the Fresenius Medical Center at 219 E 34th St. Price had driven himself there.
His car was in the parking lot of the dialysis center, the center was closed, locked and not answering the phone, Price's family said.
The family said they tried to contact the center, then put out a message on Facebook. After getting others in the community to call, police went to the center and found Price dead on the bathroom floor around 9 p.m. His family said his treatment should've been complete around 3:30 p.m.
Police say after completion of his treatment, Price was seen leaving the treatment area and stepping into the lobby, where he used the bathroom. Employees had left for the day and did not check the bathroom before locking up the building, police said.
After Price's daughter went looking for him and saw his car in the parking lot, police say they searched near the building, but all the doors were locked. Price's daughter's Facebook post reached someone who knew the assistant manager of the facility, who arrived and unlocked the doors for a further search, police said.
While Price is believed to have died of natural causes, his family said the facility was "grossly negligent."
Price, a retired harness trainer from Grant Park, was a father of three.
"We are looking into the circumstances surrounding this event and will adjust any procedures as necessary once our review is complete," Fresenius Medical Care said in a statement.