Emergency flare from shipwrecked mariner sparks 16,938-acre island wildfire

A 67-year-old mariner's emergency distress flares are believed to have ignited a wildfire that has burned 16,938 acres on Santa Rosa Island after his sailboat struck rocks Friday, the U.S. Coast Guard said.

The blaze has destroyed three buildings and forced Channel Islands National Park to close Santa Rosa Island, one of the park's most remote and ecologically sensitive islands, to the public until further notice, according to ABC7 Los Angeles.

The Santa Rosa Island Fire broke out Friday after the mariner's sailboat crashed into rocks off the island's coast, forcing him to fire emergency flares as distress signals, ABC7 Los Angeles reported. Coast Guard investigators believe the flares ignited dry vegetation, touching off the blaze that has since scorched 16,938 acres.

Rescue crews from U.S. Coast Guard Air Station Ventura reached the man Saturday morning after he spent the night stranded on the island. The 67-year-old was not injured, according to ABC7 Los Angeles.

Three buildings on the island were destroyed by the fire. Channel Islands National Park officials closed Santa Rosa Island to the public until further notice, ABC7 Los Angeles reported.

Investigators have not definitively confirmed the cause of the fire. The U.S. Coast Guard said the exact circumstances remain under investigation.

Santa Rosa Island is one of eight islands in Channel Islands National Park, located off the Southern California coast near Ventura and Santa Barbara. The island is known for its rugged terrain, diverse wildlife and rare plant species, and is a destination for hikers and campers.

Santa Rosa Island remained closed to the public as of Wednesday, according to ABC7 Los Angeles. The U.S. Coast Guard said the exact cause of the fire is still under investigation.