A man who took hostages in a Pennsylvania hospital during a shooting that killed a police officer and wounded five other people highlights the rising violence against U.S. healthcare workers and the challenge of protecting them.

Investigators are trying to determine why a man targeted a Pennsylvania hospital, taking workers inside the intensive care unit hostage and holding one staff member at gunpoint as her hands were bound by zip ties.

A police officer died and others were injured in what local officials described a hostage crisis involving a man with a gun and zip ties.

A gunman and a responding officer were killed after shots were fired Saturday at a hospital in central Pennsylvania.

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.

Investigators are still trying to determine why a man targeted a Pennsylvania hospital, taking workers inside the intensive care unit hostage and holding one staff member at gunpoint as her hands were bound by zip ties.

An officer was killed, and six others were injured after a man armed with a pistol and zip ties entered into a Pennsylvania hospital's intensive care unit Saturday afternoon. Police were called to UPMC Memorial Hospital on Innovation Drive and Roosevelt Avenue in York County, Pittsburgh Action News 4's sister station WGAL reported.

Authorities say a gunman entered a Pennsylvania hospital’s intensive care unit and took staff members hostage before he was killed by police in a shootout that also left an officer dead

A man who took hostages at UPMC hospital during a shooting that killed a police officer and wounded five others highlights the rising violence against U.S. healthcare workers.