San Francisco residents were woken up by a tornado warning early Saturday morning during a powerful storm system that battered the region with heavy rain and wind.

A powerful storm swept through parts of Northern California early Saturday, knocking down trees, causing widespread power outages and prompting weather officials to issue what they said was the first-ever tornado warning for San Francisco.

A storm and wind gusts of up to 60 mph (96 kph) prompted the first tornado warning in San Francisco and caused some damage in the Bay Area on Saturday.