WAUKESHA, Wis. — It was supposed to be a celebratory night in Waukesha, Wis. 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. stormed past barricades and barreled through the crowd, striking dozens. At least five people were killed and 40 people were injured, and the numbers could change, city authorities said in a statement late Sunday. 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.
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, 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 simply “Comfort and Joy.”
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 first 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.
“Right now, I’m just angry,” Mr. Kellner said. “It seems everywhere we turn, it’s just another violent day in the U.S.”
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.”
Mr. Kotlarek said the driver appeared to intentionally steer toward people. That account had not been confirmed by the police.
“He was going from side to side, targeting people,” Mr. Kotlarek said. “The car bombed through. He was flying through there going intentionally from left to right.”
The Milwaukee Dancing Grannies, which were among the parade entrants, said on Facebook that members and volunteers had been impacted “and we are waiting for word on their conditions.” Officials with the Xtreme Dance team, another group that marched, asked for thoughts, prayers and “privacy to process the tragic events.” The Roman Catholic Archdiocese of Milwaukee said a priest, as well as parishioners and students at a local Catholic school, were among the injured.
Tom Hickey, 25, was walking near a friend’s float at the back of the parade when he heard honking behind him. A man wearing a sweatshirt and gray hat who was driving the red Ford Escape was trying to make his way through the crowd, he said. Mr. Hickey said he thought the driver was lost.
Then, the driver took a right turn onto the main parade route, gunned the engine and moved through the parade route at what appeared to be top speed, he said.
“When he made that right turn, that’s when he turned really dangerous,” Mr. Hickey said.
Angelito Tenorio, a candidate for state treasurer, had just finished marching in the parade and was circling back to Main Street when he saw the S.U.V. speeding along the route.
“All of a sudden I heard a loud bang,” said Mr. Tenorio, an alderman for nearby West Allis. “Then I heard deafening cries and screams. It was very gut-wrenching.”
He described a chaotic scene that left him stunned and shaking.
“People were running away, leaving their belongings behind, sobbing,” he said. “When the crowd cleared out, it looked like there were people on the ground who might have been struck by the vehicle.”
In a video posted on the city’s Facebook page, the S.U.V. can be seen speeding down the parade route and screams can be heard from those in the crowd. Then, seconds later, a police officer runs by, followed by a number of police vehicles as a group of children stops performing.
Don Paul Browne, a city alderman, was marching in the parade with the mayor but had already left and did not witness what happened. He said the city was celebrating its 125th anniversary.
He described the parade as a family-friendly event that draws spectators from other counties. He struggled to understand what happened, he said, because there were no political undertones or controversy connected with the parade.
Hours later, the families and band members were gone and residents were being asked to avoid downtown. But along the parade route, resting against the entrance to The Steaming Cup coffeehouse, three lawn chairs were illuminated by flashing red and blue police lights.
Two of the chairs — one pink, the other blue — were child sized.
Andrés Martínez, Livia Albeck-Ripka, Vimal Patel, Juston Jones and Elizabeth Dias contributed reporting.