Did a gig on drums in Italy many years ago on an outdoor stage. The performance area was covered but open at the back. There was a deluge as we were playing, and I look over to see water pouring in huge sheets off the back of the roof, directly into one of the stage boxes into which all the amps and equipment were plugged, and all across the floor of the stage while we're all playing away. Cue panic from me mid song, trying to attract the sound guy's attention and that of the rest of the band, which was quickly focussed when one of the amps went 'bang', leading to a very rapid stage abandonment!