FARGO, N.D. (AP) — A gunman opened fire on police and firefighters as they responded to a traffic crash in Fargo, North Dakota, killing one officer and wounding two others, the city’s police chief said Saturday.

The Fargo Police Department provided an update on the shooting on Saturday afternoon.

Chief David Zibolski said the gunman opened fire Friday afternoon for “no known reason at all” but that he was confident investigators will eventually figure out the motive.

Zibolski said Saturday that Officer Jake Wallin, a military veteran, was killed. Two other officers, Andrew Dotas and Tyler Hawes, were wounded. A 25-year-old woman was also injured during the shooting, but authorities did not say who shot her. The gunman did not hit any firefighters, Zibolski said, but a firetruck was struck by gunfire.

A fourth officer, Zach Robinson, shot and killed the suspect. The gunman was identified as Mohamad Barakat, a 37-year-old Fargo resident.

This was a heinous and unthinkable act of aggression against our officers and against our community,” Zibolski said. “That type of behavior obviously cannot stand.”

He said the state Bureau of Criminal Investigation and the FBI were investigating.

Several people have said they saw a man open fire on officers before other officers shot him.

Chenoa Peterson told The Associated Press that she saw a car crash and police standing around as she was driving with her 22-year-old daughter. Then a man pulled out a gun and began firing at police: “He proceeds to aim it and you just hear the bullets go off, and I’m like, ‘Oh, my God! He’s shooting!’”

Peterson’s first instinct was to pull over and try to help, but having her daughter there convinced her to leave. “It’s weird knowing that if you were 10 seconds earlier, you could have been in that,” she said.

One woman said she was driving when she saw the officers fall.

“I saw the traffic stop and as soon as I drove, shots were fired and I saw the cops go down,” Shannon Nichole told KFGO Radio. “My airbag went off and the bullet went through my driver’s door.”

Surveillance video provided by Fargo resident Allison Carlson captured the rapid sounds of gunfire.

Adam Dakak watched investigators for several hours after the shooting. He said police put up caution tape and marked shell casings with flags behind a rear-ended car in the parking lot of a small brick office building. The FBI and U.S. Marshals Service arrived at one point, he said.

“It just really hurt to see that because you don’t expect to see that type of stuff in Fargo,” Dakak told the AP.

Fargo Police Chief Dave Zibolski said, “One of the most horrific days in our department’s history. For no known reason at all, a violent gunman attacked our officers, firing multiple rounds, striking three of them.”

“It’s an unconscionable act. It’s hard to fathom. It’s unbelievable that something like this would happen in our community, and many of us think a lot of this stuff can’t happen. This happened. Our department right now and I’m sure our community is very heartbroken and we’re all working with heavy hearts. He was a member of our family, and he’s been taken from us far too soon, and it’s a tragedy,” said Zibolski.

By Saturday, flowers had been placed on the street where much of the investigation was focused a day earlier. A roll of bandage wrap also was on the ground.

“If everybody had not done their job they were trained to do, we could have two more fatalities. Our community is a community that stands up for each other and we’ll continue to do that,” said Fargo Mayor Tim Mahoney.

Brian Hubbard, the president of the Minnesota Law Enforcement Memorial Association, added, “When an officer dies in the line of duty in a community — any community, big community, small community, I believe it really rocks a community to its core. He comes in enthusiastically, as it looked like in the press conference, he came in enthusiastically excited for what it was he felt compelled to do.”

North Dakota Gov. Doug Burgum said he was “heartbroken” by the shooting. Burgum, a Republican who is also running for president, said it was a “tragic reminder that our law enforcement officers risk their lives every day for our safety and deserve our unwavering gratitude and support.”

U.S. Sen. Jon Hoeven expressed condolences to the family of the slain officer and said he and his wife were praying for those who were injured.

Police initially said little about the shooting, calling it only a “critical incident” for nine hours. Early details emerged from people who said they witnessed the shooting or heard gunshots. Shortly after the shooting, officers converged on a residential area about 2 miles (3.2 kilometers) away and evacuated residents while gathering what they said was related evidence.

“Someone who has served in the military and has served in hostile zones to come back as a rookie officer to have his life taken from just a cowardly evil act is just horrific,” stated Executive Director of the Minnesota Sheriff’s Association James Stuart.