The eastern end of Lance Drive. (KCAW photo/Greta Mart)

The eastern end of Lance Drive. (KCAW photo/Greta Mart)

The Lance Drive bomb mystery has been solved.

Explosives found last week at the end of Lance Drive in Sitka turned out to be no longer dangerous — in fact, bomb experts believe that they had already detonated underground years ago.

The Sitka fire department called in a military bomb squad from Ft. Richardson to assist with the case.

Last Thursday, a Lance Drive homeowner called in officials after discovering strange wires sticking out of the ground where he was building a rock wall. Authorities briefly evacuated neighboring residents and closed Sawmill Creek Road to traffic.

By Saturday, the investigating team cleared the area and cut down an 80-foot spruce tree adjacent to the wires. Unearthing what turned out to be a 30-year-old fuse, the team followed the fuse wire down eight feet to find a hollowed-out cavern, assistant fire chief Al Stevens said on Monday.

Buried dynamite had exploded years ago, creating the cavern, but the TNT was so tightly packed in the surrounding sand, it had not caused an explosion above ground. And the fuse, or detonation cord, had never burned.

Officials suspect the cache of dynamite was left over from an abandoned roadworks project designed to connect Lance Drive to Sawmill Creek Road. The project was halted after city staff determined it was too dangerous to create an intersection on that particular blind curve of Sawmill Creek Road.

Stevens said in all of his years on the job, he had never come across anything like the underground explosion site. He added that it was likely the felled spruce tree would have eventually toppled on adjacent homes as it was standing atop a hollow mound.