A young boy has been identified as the child who was among those killed after a car plowed into a Christmas parade in Waukesha on Sunday.

Jackson Sparks, 8, and his 12-year-old brother were both hospitalized in intensive care after being "seriously injured" at the parade, according to a statement released Tuesday by a local church on behalf of their parents.

Jackson, described as a "sweet little boy," died from his injuries on Tuesday afternoon. His brother "is miraculously recovering from his injuries and will be being discharged home," according to the statement.

Jackson's death marks the sixth fatality from the incident.

Of the 16 children who were admitted to the hospital following the parade, 13 remain hospitalized, according to the Children's Wisconsin-Milwaukee Hospital.

Six were listed in critical condition, three in fair condition and four in good condition, according to the hospital.

One child died from his or her injuries on Tuesday, while two others were discharged, hospital officials said in a statement.

The family of the child who died has asked for privacy.

-ABC News' Joshua Hoyos and Victor Ordonez

Darrell Brooks appeared in court for the first time Tuesday afternoon, where he sobbed as a Waukesha County prosecutor announced a sixth victim — a child — had died from injuries sustained when Brooks allegedly drove through the Christmas parade.

The prosecutor said she intends to add a sixth charge, and likely will add more if additional victims succumb to their injuries.

Brooks’ bail was set at $5 million, an amount the judge described as "extraordinarily high" as it is not possible to hold a defendant without bail in the state of Wisconsin.

"The nature of this offense is shocking," the judge said. "Two detectives not only tried to stop this but rendered an opinion that this was an intentional act."

Prosecutors also expressed concerns about Brooks’ flight history and ability to obey the obligations of the court, given his lengthy criminal record in multiple states.

"There are not words to describe the risk this defendant presents to our community," the prosecutor said.

Brooks did not enter a plea. Brooks' attorney indicated he had no means to pay for bail.

-ABC News' Aaron Katersky

Darrell Brooks, the man accused of killing six and injuring 62 when his SUV plowed into a Christmas parade on Sunday, appeared to have "no emotion on his face" while doing so, according to a criminal complaint.

At one point an officer “pounded on the [suspect's] driver’s side door yelling ‘stop,’” the criminal complaint said.

But instead, according to the complaint, Brooks kept going, and later he "appeared to rapidly accelerate" and "took an abrupt left turn into the crowd of parade participants."

The SUV "appeared to be intentionally moving side to side, striking multiple people, and bodies and objects were flying," the complaint said.

One witness told police the suspect drove "in a zigzag motion," the complaint said. "It was like the SUV was trying to avoid vehicles, not people. There was no attempt made by the vehicle to stop, much less slow down.”

Another witness told police it appeared to be "a direct intent to hit as many parade participants," the complaint said.