41.   By late Wednesday, there were more questions than answers about what caused the crash.

42.   Cell phones may not cause crashes, but talking on one may reduce the ability of a driver to compensate for the mistakes of other drivers, researchers said.

43.   Croatian authorities say the crash was caused by pilot error.

44.   Everybody worried that all those zeroes would cause computer crashes around the world.

45.   Examination of the wreckage, he said, bore out his insistence that the crash had been caused by the collapse of a tire wheel.

46.   FAA rules specify that for any single failure that can cause a crash, the likelihood must be one in a billion or lower.

47.   Federal investigators have not yet determined what caused the crash.

48.   Finding that the crash was caused by mechanical failure would be better than the alternative, but either is bad news for the economy, he said Monday.

49.   Friday marks six months since the TWA crash, with no definitive answer on what caused that crash.

50.   Four different in-air complications caused the crashes, they said.