A Wisconsin firefighter responding to a medical emergency was fatally shot and three others were wounded, including a police officer, according to reports.

The 14-year veteran of the Appleton Fire Department, whose name has not been released, responded along with other firefighters and police to a transit center about 5:30 p.m. Wednesday, according to ABC News.

While a person was being treated, “the incident escalated into shots being fired,” Meghan Cash of the Appleton police told WBAY.

“It was a very quick scene. … We had to get people to the hospital quickly. So we’re just happy we could get them there and get them the medical attention they needed,” she said.

There was no ongoing threat to the community, Cash added, but didn’t say if anyone was arrested after the incident at the Valley Transit Center.

Tori Mourning, a witness, told the ABC affiliate that at first it sounded like a lawnmower backfiring.

Then “I heard it again — I looked up because we can see the bus stop from my bedroom window,” she said.

“I saw the guy shoot a female, and she went down,” Mourning added, “and another shot was fired, and there was another male, and he went down, and then I saw the shooter flee.”

A procession was held overnight in Milwaukee as the fallen firefighter’s body was taken to the Milwaukee County Medical Examiner’s Office in a flag-draped coffin.

Appleton is about 120 miles north of Milwaukee.