With the grass growing faster than the national debt, we are all spending way too much time mowing. No real details, but evidently this was a rollover and the roll bar was in the down position.
Looks like a zero-turn mower. I wonder if he was trying to mow too steep an incline.
My guess too; each brand is different but i have seen a few tip up on inclines. Once those uphill wheels leave the ground ut is easy to pull/push the levers the wrong way and complete the rollover.
Not a fan of zero turns. If you have flat ground they are fine. I’m also not a fan of folks not reading or getting to know their equipment. Don’t respect equipment pay the price.