Ever been hit by a hailstone? Yikes! They hurt. I remember a short hailstorm back in the early 80's. I was quite amused, watching ping-pong-ball-sized hail actually bounce off the grass when they hit.
Just recently, I did a search on largest recorded stone (@ 7-inches), and the speed of hailstones (seems the larger they are, the faster they fall), but the speed can be anywheres from 10mph (small hail) up to 110mph for huge stones.
In 1986, 92 people in Bangladesh were killed during one storm. The hailstones were the size of grapefruits, and weighed @ 2lbs.
When Mother Nature speaks, we should listen.