In this Wednesday, May 15, 2019 photo, people wait as authorities investigate the scene of a shooting at the Valley Transit Center in Appleton, Wis. A firefighter responding to a medical emergency was killed in the shooting at a Wisconsin bus station that left several others injured, officials said. (Dan Powers/The Post-Crescent via AP)

APPLETON, Wis. (AP) — A call to assist a man thought to be having a medical emergency on a bus escalated into a shooting that ended with the man and an Appleton firefighter dead and two others hurt, authorities said Thursday.

The incident began at around 5:30 p.m. Wednesday as police, firefighters and an ambulance went to help a 47-year-old man arriving in downtown Appleton on a bus from out of the area, police said.

The responders gave medical help to the man, who eventually left the bus and started walking toward a nearby library, whereupon "the incident escalated," police said. Chief Todd Thomas said the man showed a handgun and exchanged shots with the police officers.

Firefighter Mitch Lundgaard, a 14-year veteran, was killed. A female bystander and an Appleton police officer were also hit. The woman was hospitalized in stable condition, and the officer was treated and released.

The 47-year-old man died at a hospital from his injuries, police said.

Tori Mourning lives across the street from the transit center and heard the gunfire.

"I looked up. I heard a pow and I thought it was the lawnmower firing. I heard it again. I looked up because you could see the bus stop from my bedroom window, looked at the tree. I saw the guy shoot a female and she went down. And another shot was fired and there was another male and he went down and I saw the shooter flee," Mourning told WBAY-TV.

Mourning said she yelled for her children as soon as she realized shots were fired.

"I screamed through my house that those are gunfire and everyone get down," Mourning said.

Appleton Fire Chief Jeremy Hansen said Lundgaard was married with three young children.

A long line of emergency vehicles escorted Lundgaard's body from the Milwaukee County Medical Examiner's Office in Milwaukee, where an autopsy was done, back to Appleton on Thursday.

Police on motorcycles led the procession as it made its way north about 120 miles (195 kilometers) on Interstate 41. Firefighters with their truck lights flashing positioned themselves on interstate overpasses as the procession passed by on the way to an Appleton funeral home.

Firefighters stood silently at the medical examiner's office as the procession began, just as they had when the body arrived in a flag-draped casket overnight.

Gov. Tony Evers sent his condolences Thursday to the family and colleagues of the firefighter.

In a statement on Twitter, Evers said that he and his wife, Kathy, "send our deepest sympathies to the family, friends (and) colleagues of the firefighter who lost their life last night."

"We stand with our brave first responders ... as they mourn this loss," Evers said.

In this Wednesday, May 15, 2019 photo, authorities investigate the scene of a shooting at the Valley Transit Center in Appleton, Wis. A firefighter responding to a medical emergency was killed in the shooting at a Wisconsin bus station that left several others injured, officials said. (Dan Powers/The Post-Crescent via AP)
In this Wednesday, May 15, 2019 photo, authorities investigate the scene of a shooting at the Valley Transit Center in Appleton, Wis. A firefighter responding to a medical emergency was killed in the shooting at a Wisconsin bus station that left several others injured, officials said. (Dan Powers/The Post-Crescent via AP)