Surveillance video shows the suspects placing a six-pack of soda in the door so it wouldn't shut. The suspects then smashed a glass top and emptied display cases and drawers filled with jewelry.
One suspect forced an employee into a backroom. There are no reports of anyone being injured.
The getaway car, which turned out to be stolen, was located a few blocks away.
Anyone with information on the robbery should call the Whittier Police Department at (562) 945-8250.