PITTSBURGH, Pa. — Brown silt, illuminated in the ghostly globe of light cast by Paul Warchol's headlamp, glided into the divers mask 2 inches in front of his eyes.
The tether connecting him to the boat above suddenly snagged on something in the black, watery expanse behind him. A moment later, his headlamp cut out. His communication system followed, abandoning him to the hollow, rasping sound of breaths drawn from his air tank.
Alone in the darkness, nearly 18 feet below the Allegheny River's surface, Warchol willed off the clawing panic.