The M62 coach bombing happened on February 4 , 1974 , when an IRA bomb exploded in a coach carrying off-duty British Armed Forces personnel and their family members.
Twelve people - nine soldiers and three civillians - were killed by the bomb, which consisted of 25 pounds (11 kg) of high explosive hidden in a luggage locker on the coach.
The coach had been specially commissioned to carry Army and RAF personnel on leave with their families from and to the bases at Catterick and Darlington during a period of industrial strike action on the trains.
The vehicle had left Manchester and was travelling eastbound along the M62 in West Yorkshire when the bomb went off, just after midnight., near the Hartshead Moor service station.
Most of those aboard were sleeping at the time. The blast, which could be heard several miles away, reduced the coach to a "tangle of twisted metal" and threw body parts up to 250 yards .
The explosion killed eleven people outright and wounded over fifty others, one of whom died four days later.
Following the explosion, the British public and politicians from all three major parties called for swift justice.
The ensuing police investigation led by Detective Chief Superintendent George Oldfield resulted in the arrest of the mentally ill Judith Ward who claimed to have conducted a string of bombings in Britain in 1973 and 1974 and to have married and had a baby with two separate IRA members.
Despite her later retraction of these claims, the lack of any corroborating evidence against her, and serious gaps in her testimony, she was convicted in November 1974.
Judith Ward was finally released in 1992, when three appeal court judges held unanimously that her conviction was "a grave miscarriage of justice".
There was a memorial to those who were killed, situated in the entrance hall of the westbound section of the Hartshead Moor service area, which was used as a first aid station for those wounded in the blast.
There is now a larger memorial, set away from the foyer of the Hartshead Moor service area, following a campaign by relatives of the dead.