MORAGA (KRON) — Police believe a vape pen may be the cause of a fire in Moraga earlier this month that burned 40 acres and prompted overnight evacuations in a neighborhood.

The fire was first reported just before 1 a.m. on Oct. 10 on Merrill Circle North in Moraga.

Police confirmed Monday a vape pen was discovered in the area where the fire started.

The vape pen is a “possible cause of the fire,” according to Moraga’s chief of police.

The fire was last reported at 40 acres.

Residents were under mandatory evacuations as the fire burned.