California has experienced its strongest earthquake in decades, leaving towns without power and scores of people injured, while emergency responders and government officials scramble to ameliorate the situation and assess damages.

The 6.0 magnitude earthquake struck a little before 3:30 a.m. local time some six miles southwest from Napa near the town of American Canyon in northern California, according to the U.S. Geological Survey.

The earthquake caused extensive structural damage to the town's historic downtown area, including to the historic Napa Valley Courthouse, which lost part of its roof. Home to California's wine country, the region reported extensive damage to residential areas as well, reports USA Today.

Four mobile homes were destroyed, and two others caught fire in northern Napa. Queen of the Valley Medical Center, a local hospital, reported three serious injuries, including one child, as well as others with minor injuries.

"There's collapses, fires," said the Napa fire captain, Doug Bridewell, according to The New York Times. "That's the worst shaking I've ever been in."

This is the strongest earthquake to affect the area since a 6.9 magnitude earthquake that hit Loma Pietra in 1989. There have been reports of power outages in various areas near the epicenter.

"A quake of that size in a populated area is of course widely felt throughout that region," Randy Baldwin, a geophysicist with the United States Geological Survey. "The 6.0 is a sizable quake for this area. It's a shallow quake. It's about 6 miles deep. We received hundreds of reports on our website from people that felt it in the surrounding area."

According to the Los Angeles Times, 50 gas lines and 30 water lines were ruptured by the earthquake and PG&E reports that more than 42,000 people lost power north of the Bay Area in the towns of American Canyon, Napa, St. Helena, Santa Rosa and Sonoma.

The California Highway Patrol sent out workers to inspect roads and bridges soon after the quake struck and found damage on California 121 and 29, reports the LA Times. An overpass on California 37 had damage, according to the California Highway Partrol, and was closed briefly but reopened at 6 a.m.