The first of three underwater crossings beneath Boston Harbor, the Sumner Tunnel, was named after William Hyslop Sumner and opened on June 30, 1934. First known as the East Boston Traffic Tunnel, it was then the only tunnel, and cars traveled in one lane in both directions.

On April 10, 1932, a worker tied in the reinforcing rods of the curved ceiling to be buried in
the concrete. Reports at the time said that the level of safety was such that if the outside coating of cement between the steel and the mud were to wear away, and if the steel itself were to corrode, this inside 18-inch wall of concrete would continue to stand.

LANE TURNER AND LISA TUITE