On 20 Aug 1868 the Irish Mail train collided with goods wagons. The force of the collision derailed the engine, its tender and the leading guard's van. Two runaway wagons next to the brake van, which carried 50 wooden barrels, holding about 1,700 gallons of paraffin oil caught fire. The engine, tender, guard's van and the first three-passenger carriages were instantly enveloped in dense smoke and flames, which soon spread to the fourth carriage and the front of the leading post office van. This prevented any immediate attempt to rescue the occupants of the first four carriages, who all died.

Henry Maxwell 7th Baron Farnham (age 69) and his wife Anna Frances Esther Stapleton (age 63) were killed.