MILFORD - Fire officials evacuated nearly a dozen businesses this afternoon after an excavation mishap caused a major gas leak in Milford.The gas leak occurred on Boston Post Road near High Street by I-95 Exit 37. Fire officials say that a private construction crew was digging along the road when the gas leak sprung. Authorities say the excavation machine cut off a piece of a 12-inch high pressure gas line. Some local employees said they started to smell the gas inside their offices before they got the alert to move out.Authorities say that only one area has been affected. At this time, no injuries have been reported.