On 10 May 1970, Sabo was a member of B Company 3rd Battalion, 506th Infantry Regiment, 101st Airborne Division. Sabo's platoon was part of a force of two platoons from Bravo Company on a mission to Se San, Cambodia to attack a force of NVA troops which had used the area as a staging ground for the Tet Offensive and other attacks. There, they were ambushed by a large force of 150 NVA troops hidden in the jungle and the trees, which had caught the U.S. force in the open and unprepared. Sabo, who was at the column's end, repeatedly repulsed efforts by the North Vietnamese to surround and overrun the Americans. As this battle was continuing, a North Vietnamese soldier threw a grenade near a wounded U.S. soldier lying in the open. Sabo ran out from a small tree that had been providing him cover, draped himself over his wounded comrade as the grenade exploded. Then, after absorbing multiple wounds from the grenade blast, Sabo attacked the enemy trench, killing two soldiers with a grenade of his own, and helped the wounded U.S. soldier to the shelter of a nearby treeline. Later, with the Americans running out of ammunition, Sabo again exposed himself to retrieve rounds from Americans killed earlier in the day. Sabo then began redistributing ammunition to other members of the platoon,including stripping ammunition from wounded and dead comrades. As night fell, the North Vietnamese refocused their efforts from wiping out the American force to harassing the helicopters that were carrying more than two dozen wounded U.S. soldiers. As that occurred, the remaining platoon from Bravo Company broke through the North Vietnamese lines and relieved the other two platoons as the first medical helicopter arrived and loaded two wounded soldiers under heavy fire. Sabo again stepped out into the open and provided covering fire for the helicopter until his ammunition was exhausted. He was killed under heavy fire by the North Vietnamese while trying to reload.