Sorry, Susan, I sympathize with your situation whatever the cause.
But it looks to me like there's at least an even chance that the strut went first. Without support the shaft would certainly flail around enough to reduce the clearance to allow a glancing blow, which would be bad news for the first blade to hit. The damage apparent at the stern tube in the downward direction is further evidence of a flailing shaft, but the chicken or the egg debate can crop its ugly head here too.
Can't say I'm crazy about that strut design, the upper portion creates a real "hard point" where any vibration/stress could lead to weakening that would be very hard to spot with the end result a sudden failure that may have occurred.
Having said that, and having experienced a one-blade-open folder there's no question that it can produce unbelievable vibrations and imbalance and have no problem imagining such a failure tear out a strut, especially a poorly designed one.(and especially at speed)
The real problem is going to be getting an accurate determination of what really happened with all the fingerpointing going on.
Last edited by Faster; 04-18-2006 at 11:22 PM.