RENO, Nev. — State and county officials in northern Nevada have declared a state of emergency as a wind-whipped wildfire in Reno has destroyed more than 20 homes and forced the evacuation of thousands.

The 400-acre blaze started about 12:30 a.m. Friday in the Caughlin Ranch area.

The Reno Gazette-Journal reports about 9,000 residents are under a voluntary evacuation order. Police went house to house in the middle of the night warning residents to leave their homes.

Authorities say one person suffered a cardiac arrest and several others suffered smoke inhalation.

Ninety schools were closed to clear the roads of school traffic and make way for emergency workers. About 125 crew members are fighting the fire.

High winds are expected until about midnight.

Firefighters don’t know what caused it.