It's been more than two years since a bus carrying Chippewa high school students slammed into an overturned truck. But it may still take months for the first civil lawsuit from that fatal crash to get underway.

That's because a prominent expert witness for the defense has died.

Dr. Arthur Ginsburg died in January, but the defense said last week it needed more time to find a replacement.

Ginsburg's testimony helped exonerate Michael Kozlowski, the driver of the overturned rig, in a criminal trial last year. Ginsburg and the defense argued that the bus driver should have been able to see the disabled rig and stop in time.

Instead the bus crashed into the truck, killing five people and injuring dozens of others.

Last week Rusk County Judge Frederick Henderson granted the postponement of the civil trial but he didn't schedule a replacement date.

(Copyright 2008 by The Associated Press. All Rights Reserved.)