WAUKESHA, Wis. — Wisconsin state troopers and police officers from across suburban Milwaukee had largely blocked off downtown Waukesha on Monday morning as they continued to investigate why the driver of a red S.U.V. barreled through a Christmas parade the day before, killing at least five people and injuring more than 40 others.
It was supposed to be a celebratory night in Waukesha. Dance groups and high school bands and politicians were marching along Main Street in the Milwaukee suburb’s Christmas parade, which was returning from a pandemic hiatus.
Then, just before 4:40 p.m., the driver of a red S.U.V., said to be a Ford Escape, stormed past barricades and into the crowd, striking dozens. City authorities said in a statement late Sunday that the number of dead and injured could change.
Area hospitals reported treating dozens of patients, including many children. It was unclear what might have motivated the episode.
“Today our community faced horror and tragedy in what should have been a community celebration,” said Mayor Shawn Reilly, who described seeing smiling children and happy parents when he marched along the parade route before the incident. “I’m deeply saddened to know that so many in our community went to a parade but ended up dealing with injury and heartache.”
Chief Daniel Thompson of the Waukesha Police Department said on Sunday night that a person of interest was in custody and that there was no further threat. Eyewitnesses described the driver as male, but that was not confirmed by the police. Chief Thompson said shots were fired by the police at the driver.
A spokesman for Children’s Wisconsin said that hospital, which treats only pediatric patients, had admitted 15 people on Sunday. Details about their conditions were not immediately available. Another hospital, Aurora Medical Center–Summit, said in a statement that it was treating 13 patients, including three in critical condition. Officials at Froedtert Hospital said they also had received patients but did not specify how many.
This was the 58th Christmas parade for Waukesha, an annual event that was canceled last year because of the pandemic. The theme of this year’s event was simply “Comfort and Joy.”
The tragedy spoiled what participants and onlookers described as a joyous night in Waukesha, a bedroom community about 20 miles west of Milwaukee. More than 60 entries, from the Waukesha Fire Department to the Old Car Club to Santa Claus, were scheduled to march through downtown.
This was the 58th Christmas parade for Waukesha, an annual event that was canceled last year because of the pandemic. The theme of this year’s event was “Comfort and Joy.”
Witnesses described scenes of chaos and tragedy in the moments after the driver passed through.
Mikey Randa, 14, said he was marching in the parade with his high school football team when he saw a young girl hit by the car.
“The car just flew past us, there was a lot of panic,” he said, adding that he initially didn’t grasp what had happened. Mr. Randa said he then saw five or six bodies lying on the ground. “I’m still in a bit of a shock,” he said.
Jason Kellner, 49, said that he had just watched his son, a drum player in the Waukesha South High School marching band, pass by when he saw a red Ford Escape heading toward the crowd. After passing through an intersection, Mr. Kellner said, the car “started mowing people down.”
“I’ve never felt a worse feeling; wondering what I’m going to find when I get to my kid,” Mr. Kellner said of the moment he ran toward his son, whom he found standing unharmed by the side of the road.
Mr. Kellner said he pulled a bloody saxophone off the street and saw several people, apparently injured, on the ground.
Tyler Kotlarek, 28, was watching the parade with family members when they heard what at first sounded like cheering, but then they realized “it was screams,” he said. “It was the worst thing I’ve ever seen in my life.”
Waukesha is an upper-middle-class bedroom community about 20 miles west of Milwaukee.
It made headlines in 2014, when two 12-year-old girls who wanted to gain the favor of a sinister fictional character called Slender Man lured a classmate to a park and stabbed her 19 times, shocking parents in Waukesha.
The girls told the authorities that they believed Slender Man was real, that he lived in a mansion in the Northwoods of Wisconsin and that they needed to kill to prove themselves worthy to him. They were charged as adults with attempted murder.
In September, one of the attackers — Anissa Weier, now 19 — was ordered released from a psychiatric hospital. She had been sentenced to 25 years in the Winnebago Mental Health Institute. The other attacker, Morgan Geyser, was sentenced to 40 years in a psychiatric hospital.
Politically, Waukesha is known as one of the “WOW” counties surrounding Milwaukee (the others are Ozaukee and Washington) that are a key battleground in Wisconsin, itself the narrowest of battleground states.
“If Wisconsin is the bellwether state for November’s general election, then Waukesha County might be the most important area of the most important state,” Astead W. Herndon, a New York Times political correspondent, wrote in July 2020.
Waukesha and other well-educated, affluent counties north and west of Milwaukee have for decades delivered Republican landslides, defying a Democratic shift in suburbia in other Northern states. Yet while then-President Trump easily won Waukesha County in 2020, his margin fell by over five percentage points compared with 2016, and President Biden came out ahead in the city of Waukesha.