A large lakeside house in Mahtomedi was destroyed early Friday morning by a fire that high winds spread to two neighboring homes, damaging them as well.

Two families were evacuated, but no one was hurt in the blaze, which was reported shortly after midnight, Mahtomedi Fire Chief Terry Fischer said.

Cause of the fire is unknown, he said. The state fire marshal is investigating.

Fischer said the fire was first reported by someone across a bay on White Bear Lake, who said they saw a fireball and flames in the vicinity of the homes in the 200 block of Park Avenue.

By the time fire crews arrived, the blaze had already engulfed the house and winds gusting off the lake were blowing embers and ashes to the homes next door, he said.

Officials found no one home at the house where the fire started, but Washington County deputies awakened residents in the neighboring houses and got them out safely, Fischer said.

The two most heavily damaged homes were built in 2007 on White Bear Lake and valued at $1.8 million and $1.7 million, according to Washington County property records.

In addition to Mahtomedi, fire departments from Lake Elmo, Oakdale, Stillwater and White Bear Lake responded, he said.