"While the future of the MATTs was in doubt, tragedy befell the Team when four people died, Corporal T .D. Blackhurst, AATTV , Lance Corporal J .F .Gillespie, 8th Australian Field Ambulance, Captain Albertson, US Army, artillery observer and adviser, and a South Vietnamese soldier of 302nd RF Battalion. 'Blacky' Blackhurst was the only corporal of AATTV and only MATTs member killed in action. On 17 April 1971, as a member of MATT 3, Blackhurst was attached to a fifty-man company patrol of 302nd RF Battalion during Dong Khoi operations. The aim of the patrol was to assist in the clearance of the enemy from his haven in the deep crevices and caves of the densely timbered, boulder-strewn Long Hai mountains in southern Phuoc Tuy province. Few Australian or government forces had ever emerged from this area without loss.

At approximately 3.20 p.m. the company was at a high point deep in the mountain complex when a Vietnamese soldier stood on a mine which detonated and caused four casualties. Blackhurst and Albertson went forward to help the wounded. The corporal radioed his team leader, Warrant Officer 2 B.L. Maher, that it would be easier to arrange a helicopter evacuation on the spot rather than try to move the casualties to more open ground. Standing patrols were placed around the area and a RAAF helicopter with accompanying gunships, unable to land because of the boulders, was soon hovering over the position at tree-top level.

Blackhurst competently organized the wounded and directed the pilot. Rescue equipment was lowered under Blackhurst's supervision and the crew began winching the first casualty aboard. The Vietnamese soldier was dangling in mid-air when a machine-gun suddenly commenced firing from outside the perimeter, hitting the helicopter and killing Lance Corporal Gillespie, the medical NCO on board. The helicopter crashed to the ground and exploded in flames engulfing Blackhurst, Albertson, and the wounded man on the winch. The crew, injured and shocked, managed to escape.