Sheriff’s Department arson investigators were looking into an early morning apartment fire in Canyon Country that caused about $70,000 in damage Friday.

The fire at Sierra Canyon Apartments, 27520 Sierra Highway, broke out shortly after midnight, according to a county fire official.

Stephanie English, spokeswoman for the Los Angeles County Fire Department, said firefighters found the blaze in the bedroom of a second-floor apartment unit and extending into the attic.

Firefighters were able to hold the fire to the single unit, English said.

English estimated the total property loss at $50,000, with an additional $20,000 in damages to possessions inside the property. No serious injuries resulted from the fire, English said.

The cause of the fire was unknown; an arson investigations spokesman said the department routinely investigates fires that cause damage exceeding $7,500.