Plane Makes Emergency Landing When Fire Breaks Out After Takeoff, 4 Hospitalized United Flight 2664 was grounded shortly after takeoff after a passenger's external battery pack went up in flames.

A New Jersey-bound United Airlines flight turned around shortly after taking off in San Diego Tuesday morning after a first-class passenger's external battery pack caught fire and injured at least four people, according to San Diego Fire-Rescue.

The battery back blew up in flames just 10 minutes into United Airlines Flight 2664 en route to Newark Liberty International Airport at around 7:15 am local time on Tuesday, officials said.

The passenger, who was seated in the plane's first-class cabin, plugged the external pack into their cell phone upon take off. It was contained and placed inside a fire-safe bag by the flight crew.

"Our crew acted quickly to contain the device and medical personnel met the aircraft upon arrival at the gate," United said in a statement. "We thank our crew for their quick actions in prioritizing the safety of everyone on board the aircraft."

At least four passengers were transported to the hospital while two others were injured but declined transportation to medical care. The rest of the passengers from the flight were medically evaluated while United reported that "several" flight attendants had also been taken to the hospital.

SDFD crews at SD Intl Airport for a plane that came in w/ an external battery pack on fire in the cabin. Flight crew prevented the fire from spreading to the cabin. Two patients transported to hospital and more being eval'd. #batteryfire pic.twitter.com/BL5MrBAGUO

— SDFD (@SDFD) February 7, 2023

One passenger, Caroline Lipinski, witnessed the incident and knew something was awry when she noticed smoke coming from the first-class cabin.

"[The passenger] threw something on the ground and it was a battery charger pack or something from his laptop, it burst into fire," she told local outlet CBS8. "There was smoke in the cabin, I was terrified."

According to flight tracking site FlightAware, Flight 2664 was only in the air for 44 minutes before it emergency landed back in San Diego.

Flight data for United 2664 via FlightAware

According to the Federal Aviation Agency, lithium batteries "can be dangerous on aircraft if not packed or shipped properly."

The FAA is currently investigating the incident.