Delta Airlines, Loss of Cabin Pressure

A Delta Airlines Boeing 767-300, registration N1608 performing flight DL-31 from London Heathrow,EN (UK) to Atlanta,GA (USA), was enroute at FL320 about 110nm west of London when the crew initiated an emergency descent due to the loss of cabin pressure, the passenger oxygen masks were released. The aircraft dumped fuel and returned to London Heathrow for a safe landing on runway 27R about 80 minutes after leaving FL320. The occurrence aircraft was able to depart London after 21 hours on the ground and positioning to Atlanta as flight DL-9965.

Source: http://www.avherald.com/h?article=4acfac04&opt=0