On 27 July 2008 investigators announced that they believe a malfunctioning oxygen canister caused a minor explosion on a Qantas passenger aircraft two days earlier, forcing the flight to make an emergency landing in the Philippines. The London-to-Melbourne flight was jolted by a loud bang midway through its trip on 25 July, and ground crews discovered a 9 ftt/2.7 m hole in the fuselage after the aircraft landed. All passengers and crew were unharmed in the incident, and security officials launched an investigation into what caused the damage. Transportation safety experts stated that tests for residue from explosives came up negative, and a senior official in the Australian Transport and Safety Bureau claimed it was not a “security-related event.” The aircraft had been carrying a supply of oxygen bottles in the cargo hold.