Local and state fire officials are continuing to investigate the Sunday morning blaze at Petersen Excavating, Clarks Grove Fire Chief Carl Anderson said late Monday afternoon.

Anderson said it would be a couple of days until the cause has been determined. The state fire marshal has been called in to assist.

Nine fire departments were called to douse the blaze at the business, 24302 755th Ave., just north of the Albert Lea city limits.

The loss is estimated at $1 million.