The shooting happened around 10:30 a.m. Thursday at the Manatawny Manor Nursing Home in East Coventry Township.
The man was taken to Reading Hospital with a self-inflicted gunshot wound to the head and died overnight, the Chester County District Attorney's Office said on Friday.
Authorities said there was another patient inside the room when the shots rang out but there were no reports of any other physical injuries.
The weapon was recovered at the scene.
Shawn Johnson, who is an employee of the nursing home, says he had the day off but went to the facility to check on the patients and staff.
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"It's crazy. I was shook up when I heard about it," said Johnson.
Pat Erb says her father lives in the facility and was inside his room when the shooting happened.
"He said he just heard some ruckus going on and they closed his room door," said Erb.
Anyone with information on the incident is asked to call Chester County Detectives at 610-344-6866.