A 1,700-plant marijuana grow house in Southern California erupted in flames when a living room compost pile ignited. Los Angeles County sheriff's investigators say the fire broke out about 11 a.m. Monday in a one-story home in the unincorporated north San Gabriel area. Detective David Mertens told the Pasadena Star-News that a man was seen running from the home but there are no arrests. Mertens says gangs rent out homes to raise pot and investigators find a couple of similar marijuana grow houses each month.