More than 500 Cuban immigrants have come ashore in the Florida Keys since the weekend, the latest in a large and increasing number who are fleeing the communist island. The influx is stretching thin U.S. border agencies both on land and at sea. It is a dangerous trip, with unknown thousands having perished over the years. But an increasing number of Cubans are taking the risk amid . Since Oct. 1, about 4,200 have been stopped at sea — about 43 a day. The Coast Guard tries to interdict Cuban migrants at sea and return them to the island, but many make it to shore.
