Shortly after 3 a.m. on January 9, 2018, an intense downpour fell on the foothills above Montecito, where just a month before, the Thomas Fire had incinerated the native vegetation, creating a geological force most of us had never witnessed: a “debris flow.”
Defined as “a fast-moving mass of material — slurries of water, rock, soil, vegetation, and even boulders and trees — that moves downhill by sliding, flowing and/or falling,” that debris flow would soon become a defining tragedy for our community.
In the hours following the rain burst, the debris flow grew as high as 15 feet as it surged down the canyons at speeds up to 20 miles per hour. It consumed everything in its path. Huge sandstone boulders were swept along like ping-pong balls. It uprooted dozens of oak trees and obliterated buildings. The fast-moving wall of mud and debris became a liquid battering ram as it headed toward the sea.