PORTLAND, Ore. -- Firefighters were investigating a possible arson at a county mental health clinic in North Portland.

Crews were called to the Multnomah county center on 3034 NE MLK just before 10 p.m. Monday to find smoke coming from the roof, spokesman Lt. Allen Oswalt said.

Firefighters spent all night fighting the blaze and estimated damage at a total of around $600,000.

Investigators called the fire suspicious.

Multnomah County Health worker Dave Austin said the staff were concerned they wouldn’t be able to reach some of the patients because their contact information was lost in the fire.

"I can assure you that our department of county human services staff and I will do everything we can to make sure mental health clients continue to have access to services," commission chair Ted Wheeler said.

"We'll make every effort ot make sure clients don't fall through the cracks."