Violence at hospitals is on the rise, often in emergency departments but also maternity wards and intensive care units, hospital security consultant Dick Sem said.

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.

The man who authorities say entered a Pennsylvania hospital with zip ties and a pistol over the weekend had recent contact with the hospital's intensive care unit, where he took staff members hostage and was killed in a shootout that left a police officer dead and others injured.

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.