A memorial is growing as a Pennsylvania community mourns the loss of a police officer on Saturday. The officer was killed in the line of duty when a gunman opened fire inside the UPMC York Memorial Hospital.

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.

One officer was killed and at least five others were were shot in a hostage situation at a hospital in York County, Pennsylvania, according to state officials.