June 21 1976 / fromthearchive / Globe Staff photo by Edward Jenner / The then named Dorchester Bay Bridge at Morrissey Boulevard stayed open during the first Massachusetts state employees strike. Bridge tenders at drawbridges in Dorchester and on the North Shore left the bridges in the raised position as required by Federal law when they left their jobs at midnight.Cars were forced to turn around and come back the wrong way on the boulevard. Supervisory personnel later lowered the bridges.