San Jose, Calif. ? A magnitude 4.2 quake struck the San Francisco Bay area at 4:42 a.m. PDT Friday, knocking out power to 4,600 homes in Oakland, damaging some stores and snapping at least one gas line.

Shattered wine bottles line the aisle of a Montclair, Calif., liquor store after a 4.2 magnitude earthquake shook the San Francisco Bay Area early Friday. Local businesses sustained damage to their shop windows and merchandise, but no major injuries were reported.

There were no immediate reports of injuries from the quake, which was centered in the Oakland Hills but was felt as far away as Half Moon Bay, according to the U.S. Geological Survey.

The quake jolted and damaged a switch that controlled the flow of power to thousands of Oakland homes, said Susan Simon, spokeswoman for Pacific Gas & Electric.

One Berkeley resident said the quake woke her up and that she felt about 30 seconds of strong shaking.

Her home suffered no damage, but the quake snapped a gas line in the Oakland home of Kirk van Moon, who evacuated his family to their camper-van in the driveway. Their house in Montclair is about two miles from the quake’s epicenter.

“My fleeting memory as I left the house was seeing my alarm clock falling off (the bedside table) and hanging by its cable upside down,” he said. “It felt funny to walk into the kitchen this morning and see all of the cabinets slightly open. Something definitely went rolling through here.”

The van Moon’s experience was likely isolated: PG&E spokesman David Eisenhauer said the utility hadn’t received many calls, but that crews were out checking lines this morning. “It’s a good reminder that people should know where their gas shutoff valve is,” he said.

Shopkeepers in the Oakland hills found merchandise shaken loose and damaged.

“We’ve got books all over the place, drug items fallen in the pharmacy,” said Joe Sullivan, whose shop houses the Book Tree and Montclair Pharmacy. The damage wasn’t as bad as the store suffered in the 1989 Loma Prieta quake, he said.

Some expensive books were damaged, but the new Harry Potter novel was packed up safe and sound, he said.

“Harry Potter didn’t get killed in this event,” Sullivan said, adding that he hasn’t yet read the book, which was being released at midnight Friday night.

The shaker was the most intense to hit California since a 4.3 magnitude temblor rattled the Santa Cruz Mountains near Hollister on July 2. It was the largest to strike the region since a 4.2 magnitude quake shook Lafayette on March 2.