Three men, one armed with a handgun and two with hammers, robbed a Costco in Pacoima Monday morning before fleeing, authorities said.
Los Angeles police said they received multiple calls about the incident around 10:40 a.m.
A cellphone user captured the robbery on film, which shows customers panicking as two men dressed in black took handfuls of jewelry. One of them appears to break a jewelry display's glass with a hammer before grabbing some merchandise. Both of their faces were covered.
However, police later described the men as all white and in their 30s. No injuries were reported.
"They were hitting the glass where the jewelry was, where the rings were," a woman who was shopping in the store, who asked to remain anonymous, told KTLA. "So the glass is shattering ... and they were just throwing stuff into a bag."
"People were running out the emergency exits," she said. "It was just absolute chaos."
The thieves took a "significant amount of jewelry," Capt. Aaron Ponce said. They fled shortly after the incident in what appeared to be a silver 2012 or 2013 C-Class Mercedes with paper plates that read "Keyes auto."
A man named Steve said he saw the men actually get out of the vehicle before heading into the store.
"I saw three guys jump out," he said. "They were wearing jackets, hats and bandanas on their faces, up to their eyes."
He told his family to run from the area. And just as the men ran into the store, he noticed a Costco employee hit a button on a nearby wall that set off an alarm.
"It was a matter of seconds," the anonymous female customer said. "You could tell it was very well thought out ... It just happened so fast."
The vehicle involved was later spotted on Paxon Street heading toward Glenoaks Boulevard.
LAPD did not provide any further information.