Commercial insurance industry may experience an unprecedented number of claims as Hurricane Sandy approaches the Mid-Atlantic coast. “It’s fair to assume this will create serious claim issues,” said Rick Miller, chief broking officer with Aon Risk Solution’s U.S. property practice in Boston, a unit of Aon P.L.C. “We are bracing for significant damage.” While it’s too early to tell, flood damage from Hurricane Sandy is expected to be a significant portion of potential claims, industry experts say.