SANTA BARBARA, Calif. (AP) — Fire crews made significant progress overnight against a wildfire burning for nearly a week in Southern California coastal mountains, officials said Sunday.

More than 1,600 firefighters were battling the blaze in the Santa Ynez Mountains west of Santa Barbara on land and by air. They were able to stop its forward growth, and the blaze was 78% contained, federal officials said.

The Alisal Fire started last Monday and has scorched nearly 27 square miles. It is threatening about 400 structures.

A 1 1/2-acre spot fire that ignited outside a retardant line on the blaze’s northwestern corner was quickly contained by firefighters who used bulldozer and hand lines on the ground and doused the flames with water from the air. On Sunday, few hot spots remained, and fire crews were focused on increasing containment.

Cooler temperatures were forecast for Sunday, but winds with gusts around 20 mph were still expected in the area, officials said.

The fire erupted during fierce winds last week and spread rapidly down the face of the mountain range, leaping a highway and railroad to the beach below. Firefighting weather greatly improved since then, allowing airplanes and helicopters to bombard the fire with retardant and water.