Early findings indicate that the fatal explosion and fire at Robbins Lumber mill in Searsmont was accidental.

The fire earlier this month left firefighter Andrew Cross dead and 12 others injured.

In a preliminary report released Tuesday by the Maine Fire Marshal’s Office, investigators said the fire appears to have started in a mechanism underneath a silo.

They said an explosion lifted the silo off of its concrete base before collapsing and setting the surrounding area on fire.

The cause is still under investigation.