Investigation into bridge fire could take weeks

Investigators say it could be weeks before they officially determine the cause of a fire that destroyed one of Michigan's oldest covered wooden bridges.

Trevor Slater, a detective sergeant with the Michigan State Police fire investigation unit, tells The Grand Rapids Press that he has "an idea" on the origin of the Whites Bridge fire. He says officials are awaiting results of a lab analysis before being more specific.

The Ionia County sheriff's department has described the early Sunday fire as arson.

A criminal investigation is ongoing. On Monday, investigators took debris samples and walked the remains of the bridge with accelerant-sniffing dogs.

The bridge was built in the late 1860s. It crossed the Flat River in Ionia County's Keene Township, about 15 miles east of Grand Rapids.