A bus carrying high school students home from a band competition crashed into a tractor-trailer that had jackknifed on the interstate, killing four adults and an 11-year-old girl, officials said.
Twenty-nine others were injured, some seriously, in the Sunday accident, troopers said.
The semi had gone off the shoulder of Interstate 94 and jackknifed, and was blocking the westbound lane, Wisconsin State Patrol Capt. Douglas Notbohm said.
"I don't know how much opportunity there was for braking action," he said. The bus slammed into the overturned truck, but it didn't roll or catch fire, patrol spokesman Brent Pickard said.
Four students and three adults remained hospitalized Sunday night with injuries including broken hips, arms and legs and punctured lungs. Many had undergone surgery, but all were expected to recover, he said.