Homes and cars were pelted and destroyed by enormous hailstones - the size of TENNIS BALLS. The rock-hard ice balls plummeted to the ground for 15 minutes, smashing through car windscreens and sky lights. Mark Healey, 39, said his Subaru outback was covered in dents and photos show the windscreen shattered in four places with a huge hole. He said the onslaught in Louisville, Colorado, on Monday sounded like 'sniper fire' and left the roof of his house and two windows in need of repair.