(CNN) -- Police shot and wounded an armed man at a Milwaukee-area children's hospital's neonatal intensive care floor late Thursday morning, authorities said.
Milwaukee police had gone to the Children's Hospital of Wisconsin to arrest the man on a felony warrant and found him holding a child in the intensive care unit, Milwaukee County Sheriff David Clarke told reporters. Instead of surrendering, the man took out a handgun and fled down a hallway, prompting police to shoot him.
"When he was first approached, he put the baby down and he acted as if he was going to go along peacefully," Clarke said. "And it wasn't until a couple of seconds later that he bolted."
Milwaukee Police Chief Edward Flynn said the man continued to struggle with officers even after being shot in the arm. No one else was injured, he said.
Clarke said the officers didn't know the suspect's relationship to the child or whether the man -- who was wanted on a weapons charge --was armed when they first encountered him. He said the Milwaukee Police Department would investigate its officers' use of force, but told reporters it was too early to be "second-guessing" them for opening fire inside the hospital.
"These things rapidly evolve and you're going to do in your best judgment what you think is necessary to get these violent indivduals in custody, and it doesn't always go according to Hoyle," he said, referring to a strict rulebook for games. He added, "I'll tell you a better question, though: What's this idiot doing in a neo-natal care unit with a handgun?"
The hospital is located in Wauwatosa, a few miles west of Milwaukee. It was locked down because of the incident, but an all-clear was posted by mid-afternoon, the facility posted on Twitter.
CNN was first alerted to the incident by Twitter posts from CNN affiliates.