C-FTXW, an Airbus 321-200 aircraft operated by Air Transat, was conducting flight TSC443 from Cancun Intl (MMUN), Mexico to Vancouver Intl (CYVR), BC with 6 crew members and 139 passengers on board. As ground personnel was loading the passenger bags into the holds, brown smoke could be seen coming out from one of them, and actually burning through the material. The suitcase was taken away from the gate area, and sprayed with a portable fire extinguisher.
ARFF came over and inspected the bag. It was determined that the fire and smoke was caused by electronic cigarette batteries that were overheating. A second bag belonging to a travel companion was removed as a precaution.