LOS ANGELES - Things are returning to normal after passengers were left in the dark during a four-hour power outage disrupted operations at Los Angeles International Airport earlier on Wednesday evening. Power has now been restored, but during the outage everything from lighting to passenger bridges from terminals to planes were affected, according to City News Service.

The outage, which was caused by a power 'bump' at an off-airport LADWP power station, occurred about 6:30 p.m. on Wednesday.

The outage resulted in 21 flight cancellations and at least seven flight diversions, according to CNS.

It took about one hour to restore power to terminals 2, 3, 4, 5, and 6, along with the Tom Bradley International Terminal. Terminals 1, 7, and 8, meanwhile, remained under emergency power as LADWP personnel were called in to fix the problem.

Department of Transportation technicians arrived to to reset traffic signals in the terminal area.

The outage led to major disruptions with the airport putting out a tweet announcing that passengers in Terminal 1 would be re-screened as a precaution.

Power came back online in Terminal 7 about 9:40 p.m. with Terminals 8 and 1 getting power restored by about 10:00 p.m.

A short time later, power was restored to Parking Structures 1 and 7, and the LAX gateway pylons, which were also impacted by the outage.

Southwest Airlines canceled 18 flights scheduled to leave Wednesday night as a result of the outage. United Airlines canceled three, with seven others being diverted, and 15 being delayed, according to CNS.

Los Angeles Police Department deployed traffic officers to the central terminal, according to a statement from the airport.

 As of Thursday morning, power was fully restored, all TSA lanes were open, and re-screening was underway in Terminal 1.
 
The TSA issued this statement:

Due to an overnight power outage at Los Angeles International Airport, several flights were cancelled and passengers were deplaned in Terminal 1. 

An airline granted passengers whose flights were cancelled access to their checked bags, resulting in the unintentional introduction of prohibited items into the secure area of the airport. Out of an abundance of caution, TSA leadership at LAX made the decision to re-screen the passengers.

About 1,500 passengers were affected by the incident.