MONTECITO, Calif. — Chaos swept across California’s Santa Barbara County on Tuesday after a powerful overnight storm hammered the region with heavy rains, leading to the deaths of at least eight people — and a dramatic rescue of a girl pinned by debris, authorities said.

Among the hardest hit areas was Montecito, a wealthy community sandwiched between the Pacific Ocean to the south and the Santa Ynez Mountains to the north, where “massive” runoff sent mud and detritus slamming into homes, said Santa Barbara County Fire Department spokesman Mike Eliason.

The eight deaths in Santa Barbara County were “due to debris and mud flow,” a spokesperson for a joint information center said. There were 25 injuries due to the storm, officials said

Eliason said debris ruptured a gas line in one neighborhood in Montecito, causing an unknown number of structure fires. Crews have found it difficult to reach the origin because of blocked roadways.

The teen — later identified as Lauren Cantin — was discovered when firefighters using dogs in the search heard a scream. It was difficult to hear as the rain continued to fall, they said, but they pinpointed the area where the noise emanated and began to dig.