CHICAGO -- Handmade crosses are on display outside Mercy Hospital after four people, including the gunman, were killed Monday afternoon.
The crosses have the names of the two victims who worked at the hospital; Dr. Tamara O'Neal and Dayna Less. O'Neal was an emergency room physician. Less was a first-year pharmacy resident who was a recent graduate of Purdue University.
On Tuesday, their coworkers returned to the hospital to serve their patients.
"We work in trying circumstances," Dr. Patrick J. Conner said. "We deal with death and family deaths on a daily basis. There's no way we can prepare for this. There's no way we can adjust for it, but we step up to the plate when it happens."
Police said Juan Lopez, 32, gunned down O'Neal, his former fiance, in the parking lot. He then exchanged gunfire with responding Chicago police officers.
Officer Samuel Jimenez, who joined the force less than two years ago, was killed.
Less was walking out of an elevator in the hospital, when she was killed.
"We're all so unbelievably upset about this," ER Nurse Cindy Centeno said. "This is something we never expected to happen."
Lopez's body was found with a bullet wound on his head, but it is not known if he was shot by police or if he took his own life.