Years ago my '81 Suzuki 1100EX was blown over by the wind at work. Parked in a space between 3 walls, the wind funneled in, and blew over a couple of other bikes too, parked 'sidestand in' from then on.
Later, my BMW R1150RT was blown over. Famous for being shakey on the side stand, was at the MSF Advanced Rider Class. T-storms rolled in and they made us take shelter. Wind was coming from behind the RT, windscreen just like a sail. Not in gear

I saw her start to rock forward, took off across the parking lot with the instructor yelling at me to stay put. 3-4 classmates saw what was happeining and joined the race.
We ALMOST got there in time....

For those of you that have owned a Boxer Twin, you know the lovely 3-point-landing they make ( mirror, cylinder head, saddlebag - leaving the wheels parallel to the earth ) and how the $200+ mirror always breaks..
Learned to leave the bike in gear when parked ... always....
And then these was this: ( see attached pic ) - Sad pic of TTSE on her side in New Mexico in '14 at only 8000 miles...