On August 23, American Airlines Flight 357 diverted to Washington Dulles International Airport (IAD) after a passenger’s device reportedly caught fire mid-flight.

According to the carrier, the flight had a delay of over an hour before departing from Philadelphia at 10:49 a.m. Instead of making it to its intended destination, Phoenix, the Airbus A321 diverted to Dulles International Airport, a Washington, D.C. area flight hub. CBS News reported that a spokesperson of the airline said smoke from a passenger’s device allegedly caused the diversion. The type of device wasn’t specified.

“American Airlines flight 357 landed safely at Washington-Dulles (IAD) following reports of smoke from a customer’s device. The device was quickly contained by crew members prior to landing,” the spokesperson said. “We apologize to our customers for the inconvenience this caused and thank our crew for their professionalism.”

The flight carried 160 passengers and six crew members. Emergency staff were reportedly at the runway when the aircraft reached Dulles. Passenger Adriana Novello told ABC News that she suspected an onboard fire caused the disruptive smoke.

“Then I started smelling smoke, and a lot of people on the plane were coughing,” she noted. “But I looked behind me, and what we could tell was that there was something on fire in the aisle.”

American Airlines disclosed that the flight departed from Dulles the following day and arrived at Phoenix Sky Harbor International Airport at 10:58 a.m. local time. The Federal Aviation Administration (FAA) is reportedly investigating the incident.

What Should Travelers Know About Safely Taking Devices On Planes?

Travelers should be knowledgeable about safety guidelines for air travel with their devices. The FAA has specific guidelines regarding what types of electronics are allowed in carry-ons versus checked bags. The type of battery the device has will likely determine where passengers can most safely store it for air travel.

Devices with lithium metal or lithium-ion batteries must be placed in carry-on luggage. They can pose safety risks, but the FAA notes that “flight crews are trained to recognize and respond to lithium battery fires in the cabin.” Examples of those devices are laptops, smartphones, tablets, and vapes. Most power banks also have lithium batteries, so their usage on flights is increasingly being banned.

Travelers are prohibited from taking “damaged or recalled batteries and battery-powered devices” onto aircraft or placing them in checked baggage. The only exception to the latter rule is if the compromised battery has been removed from the device, or the electronic has otherwise been “made safe.”