A 26-year-old Seabeck construction worker died Friday afternoon of injuries sustained when he was buried alive in a workplace mishap a few hours earlier in South Kitsap.

Derek Calhoun was helping to install an underground tank at a home in the 3900 block of Cornwell Road when he was struck by an excavator boom and buried under a mound of dirt.

Calhoun was standing on sloping ground at about 2:30 p.m., officials said, when an excavator supporting the huge metal tank began to tip over.

The equipment operator shouted a warning to Calhoun, but the front edge of the machine knocked him to the ground as dirt fell over him.

Another employee of Cleaver Construction, Calhoun’s employer, used a second excavator to help free the victim.

By the time rescue crews from South Kitsap Fire and Rescue arrived at the scene, Calhoun was still half-buried, not breathing and in full cardiac arrest.

Nonetheless, EMTs were about to temporarily revive him — which SKFR Chief Wayne Senter described as a “once- or twice-in-a-career event.”

Calhoun was airlifted to Seattle’s Harborview Medical Center, where he died at 7:46 p.m., according to a spokesman for the Kitsap County Sheriff’s Department.