DERWOOD, Md. — Investigators say a large fire at a home in Derwood, Maryland Thursday morning occurred when someone placed fireplace ashes in a plastic container. “Always clean out your fireplace by putting it into a metal can, and then place that container itself away from the house,” says Montgomery County Fire Chief Scott Goldstein. Fire crews arrived around 5 a.m. after people inside the burning home on Willow Knoll Drive called 911. “The deck was on fire and the back of the house was on fire,” says Goldstein. “We’re estimating the damage to be roughly $300,000.” Three people, an adult and two teenagers, made it out safely. They woke up as smoke began pouring in, and the smoke alarm sounded. Firefighters rescued one Guinea pig, but it did not survive. The family fish also did not make it. Chief Scott Goldstein speaks with WTOP:

MCFRS Fire Chief Scott Goldstein speaks with WTOP News Reporter Nick Ianelli about Derwood house fire pic.twitter.com/6jkm4AqVWJ

— Pete Piringer (@mcfrsPIO) January 7, 2016

Video from the scene:

Willow Knoll Dr, Derwood, FP ashes on deck/porch was the cause; Damage >$300K; smoke alarms alerted family, no inj pic.twitter.com/o9O7QlM4YF — Pete Piringer (@mcfrsPIO) January 7, 2016