51.   But Boeing says the crash is still a mystery and there is not enough evidence to prove either theory.

52.   But crashes have long been part of the on-line world, and others approached the disruption more calmly.

53.   But even without a public declaration by investigators, the Clinton Administration has reacted as if the crash was an act of sabotage.

54.   But for the economy as a whole, the real estate crash has been a disaster.

55.   But in the chaotic hours after the crash, there were also reports that the crash could have been a tragic accident.

56.   But multi-car crashes have been a factor at Talladega and Daytona since the tracks were built.

57.   But nose dives are extremely rare, according to the Flight Safety Foundation, and such crashes usually are catastrophic to everyone aboard.

58.   But in the United States, airliner crashes themselves are very rare.

59.   But some in the timber industry say the crash is yet to come.

60.   But that crash was mild compared with what happened later that week.