How a Man in a Zorro Costume, Loud Emergency Locks Sparked LAX Panic

The chaos at Los Angeles International Airport on Sunday night, during which passengers breached security doors and spilled out onto the airport tarmac, was sparked by law enforcement detaining a man in a Zorro costume as well as loud emergency locks that sounded like gunshots, officials told ABC News today.

Panic erupted at the airport after word of a shooting threat spread -- later deemed a false alarm. But the false alarm brought travel to a halt and caused delays to pile up into Monday morning.

According to two officials briefed on the investigation, it began when a street actor in a Zorro costume was at the airport picking up a friend.

Law enforcement at the airport became suspicious of him and detained him to for questioning -- in full view of people moving through the busy Terminal 7. A small crowd saw the questioning and some of those people began rushing away from the area for fear that this was a security incident in progress, the officials said, and one passenger notified a senior TSA official that there was a security incident ongoing in the terminal.

The TSA agent put out calls to other terminals and checkpoints notifying them of an ongoing security incident in Terminal 7, the officials told ABC News.

The mounting panic caused travelers to rush for emergency exits and doors that lead to the tarmac.

Many of the doors have heavy locking mechanisms that make loud noises when they're opened, the officials said, and during the panic, the "boom" sound from the emergency locks were mistaken for gunshots.

Within minutes, travelers were posting on social media and calling in emergency reports of gunshots at the airport.

The scare resulted in evacuations from Terminals 1, 4, 6, 7 and 8, LAX officials said. The Los Angeles Police Department conducted a search, later confirming there was no evidence of any shooting and that the incident appeared to be a false alarm.

Now that officials have a complete picture of what occurred, they are looking to determine if "our own tactics contributed to the panic," one person briefed on the investigation told ABC News.

The officials who described the Sunday night's events to ABC News stressed that the November 2013 incident in which a TSA agent was killed at LAX is still fresh in the minds of all security personnel at the airport, and as a result, the tendency at LAX is to be more proactive in the face of possible security threats.