A car went airborne at the bottom of a hill and flew into a house, killing four women and seriously injuring the driver.

The sedan rolled down a steep hill, sped through a busy intersection and went airborne for about 100 feet before plowing into the house Saturday evening in the Town of Superior (search), about 390 miles northwest of Milwaukee (search).

Three elderly women in the back seat died at the scene of the crash. A fourth woman died later at a hospital, Fire Chief Brian Laverdiere (search) said.

The driver remained unconscious at the hospital, preventing investigators from learning more about what caused the accident, Sheriff Tom Dalbec (search)said. There were no witnesses.

The couple in the front seat were married, and two of the women in the back seat were the man's sisters. "The family took a big hit, Dalbec said.

The victims were coming from a church dinner. All were over 70 years old.

The sedan rammed through Jeff Christman's (search) bedroom just as he was walking in.

"I went flying and got knocked out but I'm fine," said Christman, 48. "It scared me. There was a big boom like a bomb went off."

His wife had gotten out of bed 15 minutes earlier.

"She would have been dead if she would have been sleeping," he said.