A tsunami that devastated the area around Indonesia's Sunda Strait, leaving at least 222 dead and hundreds more injured, struck fast and without warning on Saturday, NBC News reported.
While most tsunamis have seismic precursors that allow for some form of warning, an unfortunate chain of factors led to Saturday's catastrophic impact, experts say.
The tsunami, which happened between Java and Sumatra islands, was caused by the Anak Krakatau, an active volcano that has been erupting since June.
Two theories have emerged about what caused the eruption: Either an underwater landslide or a spewing of molten lava caused the displacement. Experts say it is more likely that the wave was triggered by a landslide.