There's been a few, but one I'll always remember was in summer, 1985, when I was free-fall parachuting, using a round canopy.
I'd need to check my log book to confirm, but from memory, it was a 30 second delay, with a 360 degree turn to the right, followed by a 360 to the left.
I remember having a bit of bother shuffling to get out of the door of the Islander, but made a good, stable exit, went into stable free-fall and completed the turns, back onto the original heading. When I looked down to check my altimeter ( fastened onto the chest strap of my harness ), my "boogies" (goggles as used by horse jockeys ) had ridden up, and were across my eyes, blocking my vision. I eventually managed to see the altimeter dial, which was indicating 1, 800 feet, gasped, and then deployed the canopy, which was fully deployed by around 1,000 to 900 feet. ( deployment is supposed to be initiated at 2,500 feet !!).
After checking all round, I noticed something "floating" in my left peripheral vision, which turned out to be a snapped rigging line !
Re-checking the canopy, I now saw that three complete panels had blown out, and there were tears in a further four panels !!
It would seem that, when checking my altimeter, I had gone partially "head down", into a semi track, so instead of being stable at 120 mph, I was tracking across the sky at around 140 to 160 mph, hence the shock loading on the canopy and rigging lines !!!
I had two options to choose from, with about two seconds to decide - deploy the chest-mounted reserve canopy, or stay with it as it was, ride it down and expect a very hard landing, and possible injury.
I chose to stay with it, as the reserve very well may have deployed into the main canopy, causing a "bag of washing", tangling everything, leading to a very real disaster, possible serious injury or fatality.
Of course, I landed way off the airfield, in a corner of a farmers field, narrowly missing a wooden fence - but managed a relatively soft, stand-up landing, with no injury, except maybe to my pride.
It was a long walk back to the parachute center club house, where I received a bollocking from the chief instructor, for pulling low, although, as he knew I was just renewing my Category status, and having heard my explanation, he was OK about it.
After that little "incident" I changed my altimeter to wrist-mounted !!