Dead Man's Tunnel by Sheldon Russell (2015-08-01)

Rail yard detective Hook Runyon has been reduced to rounding up copper thieves at the salvage yard when he's called to investigate a body found on the tracks. The dead man, a sergeant stationed in the remote but critical Johnson Canyon Rail Tunnel, was killed by an onrushing train. Wanting a quick resolution to avoid the chaos of a total railway shutdown, the government sends Lieutenant Allison Capron to help Hook with the case.