WALNUT CREEK, Calif. — About 80 people, some wearing ski masks and wielding crowbars, ransacked a high-end department store in the San Francisco Bay Area, assaulting employees and stealing merchandise before fleeing in cars waiting outside, police and witnesses said.

Three people were arrested while the majority got away after the large-scale theft Saturday night shocked shoppers at the Nordstrom at the Broadway Plaza outdoor mall in Walnut Creek, police said in a statement Sunday.

Two employees were assaulted and one was hit with pepper spray during what police called “clearly a planned event.”

NBC Bay Area reporter Jodi Hernandez tweeted that she saw the thieves rush into the store in the downtown shopping district in the city some 20 miles northeast of San Francisco.