Turkish Airlines Flight 981, Fontaine-Chaalis, France (1974)

Unlike most air crashes, this one was caused by a design flaw in the McDonnell Douglas DC-10, which led to the cargo hatch being ripped open. This caused a catastrophic fluctuation in the plane's cabin pressure and resulted in an explosion. 

All 346 people on this flight were killed instantly. The design flaws of the DC-10 were brought to light and blamed for this disaster. The US FAA (regulatory body) issued a notice requiring all cargo doors on DC-10s to be immediately modified to eliminate the problem.

-Picture courtesy Reuters