When the lava tube reaches the edge of the island, the hot lava drops off into the ocean.
(the lava tube; reaches; the edge of the island) (the hot lava; drops off; into the ocean; T:When the lava tube reaches the edge of the island)
the lava tube the hot lava
reaches drops off
the edge of the island
into the ocean T:When the lava tube reaches the edge of the island