I, too, knew a great local mechanic who was crushed by a vehicle falling on him. When I painted the undercarriage of my Packard, I chose items which could catch and hold the car if it fell. These turned out to be oversized Corvette tires mounted on wheels. They were thicker than me. I put one under each end of the car and on each side where the frame would catch. It did not budge with my multiple floor jack stands, but I felt better knowing I could survive if it did somehow fall. Now it is time, I need to do the same with my 1964 Imperial Crown Coupe, Be Careful guys !