MONTECITO, Calif. — A green, military-style Humvee drove along the shore here, the beach on one side, the shuttered Four Seasons Hotel on the other. Up in the hillsides, a no-go zone for civilians, multimillion-dollar mansions are flooded with mud, and cars, tossed about like playthings, are now just hunks of twisted metal, jammed against trees.

On the facades of the big homes are orange markings. An X denotes the house was checked and cleared by rescuers. A V indicates a victim was pulled, alive, from the wreckage. A V with a slash through it indicates a dead body was found.

Unimaginable tragedy struck this small, exclusive enclave, nestled between the mountains and the ocean and home to many celebrities, last week when a torrential downpour — a “once in 200 years” storm, officials are quick to say — set off deadly mudslides in a landscape that, just last month, was scorched from the state’s largest wildfire on record.