SAN JOSE (CBS SF) — As the gunshots echoed inside the Westfield Oakridge Mall Monday night, chaos and pandemonium ensued, forcing thousands of frightened Christmas shoppers to scramble for cover and rush out the doors.

San Jose police Sgt. Christian Camarillo told reporters Tuesday morning that they were “very, very lucky” no one was struck by a stray bullet.

READ MORE: Fans Rally Behind Road Warrior San Francisco 49ers; Will Tickets Be Available For NFC Championship Game?

“It was complete pandemonium. There was chaos. Again, [a] very, very active situation our officers went into,” he said. “5,000 people in there shopping, no one took a round.”

Jacob was among those in the mall. He told KPIX chaos quickly ensued.

“I heard a pop and everybody started screaming, yelling and running out of the mall,” he said. “It took people seconds (to react to the sound of gunfire.)”

RELATED: UPDATE: No Victim, No Shooter Found After Gunfire Sends Shoppers Fleeing From Oakridge Mall In San Jose

A mall employee, who wanted to remain anonymous, said he heard one loud “boom” that sounded like “a shotgun” before a crowd of shoppers began to scream and cry.

He said about 100 people ran into his store where he hid with them in a locked back room.

“I tried to be calm because I know people were panicking inside there,” he said.

Franz Hurtado said he received a call from his 11-year-old daughter who ran into the Old Navy store to hide. They continued to communicate through text messages.

“It was very, very scary,” Hurtado said. “She was brave, she was brave until now. It’s been a long day for her.”

Calls began streaming into San Jose police 911 dispatch, triggering a large law enforcement response to the mall. Camarillo said ‘over 10″ callers said someone had been shot.

Investigators say several witnesses told police the shooting was triggered by an argument of some kind outside the Forever 21 store. The gunman pulled out a gun and starting shooting, witnesses said.

Shoppers who sheltered in place inside the store waited for hours for heavily armed strike teams from the police department and sheriff’s office to methodically search the mall.

READ MORE: Hazardous Sneaker Waves Threaten San Francisco Beachcombers

Once officers began arriving, they rushed into the mall making sure the shoppers were secure.

Officers with the San Jose Police Department, California Highway Patrol and Santa Clara County Sheriff’s deputies secured entrances and exits of the mall, as a team of officers went from store to store to escort shoppers and employees to safety.

Oakridge Mall shooting investigation (CBS)

Law enforcement officers also launched a hunt for the shooter and victim.

“We searched for upwards to five hours,” Camarillo said. “We did not locate a suspect…If there is a victim out there we’d like to talk to you. We still have investigators going out to the mall today, conducting some follow-up investigation.”

He also said there were reports of an altercation before the gunfire.

“I do know there was an altercation between two different people,” Camarillo said. “People described it as a fight. There was lots of yelling. One of those people produced a firearm and fired several rounds.”

Mall officials told San Jose police that it was business as usual Tuesday morning.

“The stores are back open,” Camarillo said.

“It’s too real. But I get to hug my little girl again. It was a scary moment for the family,” said shopper Franz Hurtado who was reunited with his daughter and girlfriend once the lockdown was lifted Monday night.

But despite a nightmarish evening spent in lockdown, by Tuesday afternoon both a sense of calm and shoppers had returned to the bustling mall.

“They have a pretty decent security system. And we’re right near the policing center,” said Cliff Szczecinski. “So, I feel pretty confident that the systems in place can still protect us all here while we still shop for Christmas.”

Investigators are poring over security camera video from the mall hoping it help to flesh out exactly what happened and who is responsible.

MORE NEWS: Film Fans Tell New Castro Theatre Managers To Keep It Reel

Devin Fehely contributed to this report.