Yes, it was yet another story of a rollover. So many of us work on larger equipment, yet a riding mower is enough to kill when it's sitting on your chest.
We say it constantly: be careful. Don't get complacent. Don't work when you're tired. If it's not possible to have someone watch you, let them know where you are, and when to expect you back. Follow the manufacturer's safety manual. Don't remove safety devices. The list could go on, and on. But because the list is long, don't ignore it and hence, shorten your life.