One hospital in California's northern Bay Area has treated more than 70 patients so far from a strong earthquake that has caused widespread damage.
Vanessa DeGier, spokeswoman for Queen of the Valley hospital in Napa, says most of those were treated for cuts, bumps and bruises.
Two adults and one child, however, were said to have critical injuries at Queen of the Valley hospital.
She says the facility has treated a hip fracture and heart attack, but it's unclear if it was related to the 6.0-magnitude earthquake.
The U.S. Geological Survey says a quake hit just before 3:30 a.m. local time about 6 miles (10 kilometres) southwest of Napa, in California wine country.
Napa Division Fire Chief Darren Drake says it caused six significant fires, including at four mobile homes.
He says the damage appears significant.
Power outages and other building damage has been reported.
The U-S-G-S says it's the largest earthquake to shake the Bay Area since a 6.9-magnitude quake in 1989.