1 dead, 2 critically injured in drug lab explosion that destroyed house in Southern California

Authorities say an illegal drug lab explosion has killed one person, critically injured two others and destroyed a tiny house in Southern California.

Fire officials say the blast happened in the town of Muscoy, near San Bernardino, shortly before 7:30 p.m. Wednesday.

The 500-square-foot home sat behind a larger house. San Bernardino County Fire spokeswoman Tracy Martinez says firefighters found a man dead and a woman critically injured covered in wreckage in the basement.

Another critically hurt man was found walking nearby. All three victims were burned and hit by falling debris.

Martinez said Thursday that sheriff's investigators determined the blast stemmed from illegal drug activity.

No names or ages have been released.