Feb. 7 (UPI) -- Four people were taken to the hospital after a fire broke out in the cabin of a United Airlines flight shortly before taking off from San Diego International Airport Tuesday.
Fire officials confirmed two other people on the flight declined treatment after the fire, which was caused by an external battery pack in the cabin of the Boeing 737 Max 8 aircraft.
"Flight crew prevented the fire from spreading to the cabin. Two patients transported to hospital and more being [evaluated]," the San Diego Fire Department said in a Tweet.
United took possession of the 1.5-year-old plane in August, 2021. The plane was assembled at the Boeing plant in Renton, Wash.
The flight was headed for Newark Liberty International Airport in New Jersey at the time the fire broke out around 7:15 a.m. PST.
Pilots initially steered the plane back to the airport's Terminal 2 once they became aware of the fire, meeting first responders at the gate.
Damage did not spread through the cabin or to the exterior of the aircraft. Onboard crewmembers contained the burning object in a bag.
United initially reported the cause of the fire as a laptop but fire crews later clarified it was an external battery pack.
"We thank our crew for their quick actions in prioritizing the safety of everyone on board the aircraft and we are making arrangements to get our customers to their destinations," United said in a statement Tuesday afternoon.