Authorities described the shooting of a gunman who opened fire at a Pennsylvania hospital as “absolutely justified, beyond any and all doubt.”

Anguish and anger at the very recent loss of a loved one apparently spurred on the man who would target the intensive care unit at a Pennsylvania hospital Saturday morning, a senior law enforcement official briefed on the investigation told ABC News.

A gunman, armed with a handgun and carrying zip ties, went inside UPMC's ICU, and took staffers hostage before he was ultimately killed by police in a shootout, the York County DA said.