A man accused of killing a firefighter and injuring two other people in the California senior living building in which he lived has died.

Thomas Kim, 77, died Aug. 5 of an undisclosed pre-existing medical condition in the hospital ward of Los Angeles County–USC Medical Center, where he had been held since he was arrested June 25, the Los Angeles County Sheriff’s Department told the Long Beach Press-Telegram. Kim’s brother, George Kim, told the newspaper that his brother had diabetes and cancer.

As McKnight’s Senior Living previously reported, Thomas Kim, a resident of HumanGood’s Covenant Manor in Long Beach, CA, allegedly had been feuding with a woman who lived above him in the building and set off an explosive device in his apartment with the intent of killing her, according to prosecutors. When firefighters arrived, he allegedly shot at them. One firefighter responding to the scene died, and another was injured. Kim also reportedly injured a fellow resident of his building.

Kim had been charged with one count of murder, one count of attempted murder of a firefighter, two counts of attempted murder and one count each of arson of an inhabited structure and explosion with intent to murder, according to the Los Angeles County District Attorney’s Office.