The Tsunami sequence proved to be a complicated mix of live-action work and CG. Massive sets were built, from parts of the pier to the submerged Ferris Wheel. Many of the actors were even put in giant water tanks and tossed around to convey the effect of a Tsunami.
The scenes where Santa Monica streets were flooded were filmed at the giant water tanks built for 1997's Titanic, at Fox Baja Studios, Rosarito, Baja California, Mexico. They used real water to flood the street scenes and had the actors and stunt performers really swimming against the current. Despite the illusion of deep flowing water, the actual depth of the flowing water was only about 42 inches deep.
Highest rated episode (9.2) as of the conclusion of season 7.
The production code was 3LAY02.