The children are near a train track and observe a landslide that causes a tree to fall down the slope and destroy the embankment over the railroad tracks.
This clip provides a better understanding of the planet, Venus, along with what happens inside the planet. Neil deGrasse Tyson helps us visualize Venus like we've never seen before.
As the main characters escape, falling off the cliff, they witness the bug-like creature that attacked them fall after. As the bug and excess rocks follow the main characters into the river, the effect of the weight creates a ripple, causing a tidal wave.