MADISON, Wis. -- Dozens of cars were involved Sunday in pileups that killed at least two people on a foggy stretch of Interstate 90 east of Madison.

A truck plowed into vehicles that had braked upon reaching a fog bank, causing one pileup, Wisconsin State Patrol Lt. Laurie Steeber said. One person was killed.

A similar pileup three miles away happened when another group of vehicles on the interstate also began braking in fog, Steeber said. A second person was killed in that pileup.

At least three dozen vehicles were involved in the two pileups, Steeber said.

Thirty-five people were taken to Madison hospitals, three with life-threatening injuries, she said.

Two people were discharged from Meriter Park Hospital after treatment for minor injuries, spokeswoman Mae Knowles said. The conditions of the others were unknown.

The Madison area was fogged in all day, with visibility of an eighth of a mile or less when the pileup started, said Chris Franks, a meteorologist with the National Weather Service in Sullivan.