GLENDORA (CBSLA.com) — Remnants of a tropical storm helped firefighters make big gains against a 4,100-acre blaze burning in the Angeles National Forest.

KNX 1070′s Pete Demetriou reports crews have made so much progress fighting the Williams Fire that some residents who have been evacuated since Sunday were back in their homes.

As many as 75 people who chose to evacuate from the Camp Williams and River Communities housing areas began returning home after 9:00 a.m. after providing proper ID to authorities.

Nathan Judy with the U.S. Forest Service said the firefighting effort has improved, with containment lines are at about 50 percent of the nearly 4,200 acres burned.

“Firefighters spent the night on the line last night, and they’re going to continue to construct line again this morning and continue to try to work their way down to crews who are trying to work their way up,” said Judy.

Approximately 1,100 firefighters are working on top of ridge lines while air support continues laying down retardant in an effort to have full containment of the fire by September 13.