On March 6, 2017, about 1010 Pacific standard time, Delta Air Lines flight 429, an Airbus A319-114, N369NB, experienced an abrupt stop after being stopped with the parking break set, while taxiing for takeoff at Los Angeles International Airport (LAX), Los Angeles, California. Of the 117 passengers and crew onboard, one flight attendant was seriously injured. The airplane was not damaged. The regularly scheduled passenger flight was operating under the provisions of 14 Code of Federal Regulations Part 121 from LAX to New Orleans International Airport (MSY), New Orleans, Louisiana. The captain stated that pushback, initial engine start, and taxi were normal. When the airplane was number 5 in line taxiing for takeoff, he started the second engine. He then stopped the airplane in line, set the parking brake, and began the "delayed after-start check", when he noticed that the airplane was rolling. He then looked down and verified that the parking brake was set, which it was, and as he was applying the brakes they locked, and the airplane came to a "jarring stop". At the time of the sudden stop, the lead flight attendant (FA) was performing safety checks in the first-class galley and was thrown into the galley. After being informed of the FAs injury, the captain returned the flight to the gate where they were met by paramedics. The FA was transported to the hospital where she was diagnosed with a broken rib. Maintenance personnel examined the airplane after the accident and found the circuit breaker for the parking brake electrical control valve popped.