Ruapehu carries a large crater lake and several glaciers
and volcanic activity often interferes with those, sometimes
resulting in mudflows called lahars. These are potentially
highly destructive, and have occasionally caused serious damage
and tragedy, such as the Tangiwai disaster of 24th December
1953. In this case a lahar was triggered by the collapse of
the wall containing Crater Lake. The muddy waters rushed down
the Wangaehu Valley and swept away the Tangiwai Bridge just
minutes before the Wellington to Auckland express arrived.
151 people lost their lives.
This sign (not shown here in its actual location) is a reminder
of the dangers associated with travelling in an active volcanic
area.
