Aerial view shows the underground path of the lava tube

June 4, 1998. Aerial view to NW shows the underground path of the lava tube that leads from Pu`u `O`o (6 km in distance) over the steep pali (foreground) and to the sea. The tube's path is marked by the blue-colored fume that rises from skylights and several other weak points in the roof of the tube.