When I read structural failure I thought you were alluding to design or manufacturing failures, many aircraft were/are lost through over stressing, poking the bear is what leads to over stressing, no matter if it's a Tiger Moth or a Boeing jet (BOAC 707 Mount Fuji). Had a Cessna 210 come down a few miles from the house recently after losing a fight with thunder storm at 9,000', shed both wings, two deaths, pilot and co-pilot, the passenger was OK, he was already encased in a coffin.