 Upon hearing the explosions at the power plant, O'Brien's group detonated their explosives and both groups withdrew to the hills, just as German reinforcements were arriving at the plant.The Germans were unwilling to enter the tunnel, fearing it might be booby trapped and used boats belonging to the villagers to bypass the tunnel and reach the station.Granlund had pressed on ahead of the main group trying to find a foot bridge to aid their escape.