On Nov 11, 1973 a Varig 707 made a forced landing at Paris Orly. The aircraft was put down in an open field because an in flight fire was getting out of hand and the crew did not think they could make it to the airport. The suspicion was that a passenger was smoking in the lavatory and had put their cigarette in the waste bin, I believe this accident was the reason why smoke alarms and waste bin extinguishers were mandated in the toilets of commercial passenger transports.
http://aviation-safety.net/database/1973/730711-0.htm