Updated

Falling trees caused by brush fires have shut down a 12-mile stretch of Interstate 95 indefinitely, authorities said.

Smoke from the fires has caused periodic road closures for the past week, but the falling trees are now likely to keep I-95 closed at least several days between Port Orange and Edgewater as crews clear the debris, Florida Highway Patrol trooper Kim Miller said Wednesday.

"What's happened is that the root bulbs have burned so that the trees are now unstable and are falling into the roadway," Miller said.

Miller said it was too early to tell how long the work could take, and it was complicated by still-smoldering trees in the area.

Eighty-four wildfires were still burning in the state Thursday morning on more than 36,800 acres, according to the state Division of Forestry. The fires along I-95 south of Daytona Beach have burned at least three homes and been blamed for dozens of accidents, including four car wreck deaths.