Two people, including a 6-year-old boy, were killed and 11 others injured after a truck drove through a youth soccer game in Wichita, Kansas, on Saturday afternoon, police said, in what officials called a "heartbreaking" incident that authorities are still investigating.
First responders rushed to Stryker Soccer Complex after receiving multiple 911 calls around 3:25 p.m. CT, Capt. Aaron Moses of the Wichita Police Department told reporters at a press conference Saturday evening.
Police said the driver, who they identified only as a 34-year-old woman of Garden City, Kansas, stayed with the truck after the incident.
"She has been cooperative to this point in the investigation," he said, adding later she was in police custody.
Moses told reporters he believed one of the driver's children was playing soccer at the complex on Saturday but was not on that field at the time of the incident.
There were two juveniles who were also inside the truck at the time it went onto the field, police said.
When police arrived at the scene, the truck was located on the west end of the field and bystanders were helping to render aid to the injured people on the field, Moses said.
The two people who died -- a 6-year-old boy and a 35-year-old man, both of McPherson, Kansas -- were pronounced dead on the scene, police said.
Of the 11 people who were injured and taken to the hospital, five are children, ranging in age from 5 to 9.
The injured adults range in age from 28 to 68.
Of the injured, 10 had "traumatic injuries," Moses said, saying they ranged from bruises to "extremely severe injuries."
Police stressed they are still investigating and asked the public for patience.
"We know what happened, but now we're working very hard to find out why it happened, and we're not there yet," Wichita Police Chief Joe Sullivan told reporters.
Police said they have interviewed over 30 witnesses at the scene and are asking anyone with pictures or video of the incident to share them with investigators.
Police also credited bystanders who the police chief said "sprang into action so quickly and gave life-saving assistance until the arrival of first responders." Sullivan added, "It was truly amazing, but I think it's indicative of the of the Wichita community."
Wichita Mayor Lily Wu said "Tonight, Wichita grieves together."
"Today is a heartbreaking day for Wichita," Mayor Lily Wu told reporters. "Families came to Stryker Sports Complex to enjoy a Saturday afternoon watching their children play soccer. No one could have imagined the tragedy that would unfold."
The city of Wichita said in a Facebook post Saturday afternoon that all events at the sports complex have been canceled until further notice.
"We ask that you keep all individuals and families affected in your thoughts and prayers during this difficult time," the city said in a statement.
Kansas Gov. Laura Kelly said in a statement she was monitoring the situation and in touch with the mayor.
"My condolences go out to the families of the victims, the survivors, and all those impacted by this event," Kelly said in a statement.
In a statement, the Stryker Soccer Complex said it was praying for those affected.
"Our hearts are heavy as we process the tragic events at Stryker today," the statement said. "We are holding everyone impacted, the injured, their families, and all those who witnessed this heartbreaking event close in our thoughts and prayers."
ABC News' Chris Barry, Brianna Sanchez and Michael Pappano contributed to this report.
This is a developing story. Please check back for updates.