 The East Channel Bridge, Lacey V. Murrow Memorial Bridge, and Homer M. Hadley Memorial Bridge, carry Interstate 90 from Seattle, across Mercer Island, and into Bellevue.The City of Mercer Island was incorporated from East Seattle on July 5, 1960, and comprised all the island minus the business district.Just over one month later, August 9, the Town of Mercer Island was incorporated from that business district.