The hailstorms that rolled through the Tarrant County area Thursday morning could result in $300 million damage — and that’s just for vehicle repairs. “This is a catastrophic event for us,” said Mark Hanna, a spokesman for the Insurance Council of Texas. Hanna estimated Friday that 50,000 vehicles were damaged by the stronger-than-expected storms, which pounded cars and busted windshields from Fort Worth to Arlington. The hail fell in two bursts — about 4 a.m. and about 6:30 a.m. — and varied in size from blueberries to tennis balls.