BLOOMINGTON (CBSLA.com) — Investigators are working to determine if two fires at Bloomington High School early Friday morning are related.

Firefighters were called out to the campus, 10750 Laurel Ave., at about 2:48 p.m. Friday morning and found one portable classroom with heavy smoke showing. The fire was knocked down in 13 minutes, and no injuries were reported.

It wasn’t the first call at the school that morning – San Bernardino County firefighters were called out to a report of trees on fire, at a different portion of campus.

Investigators are working to determine if the fires are related. An estimate of damages was not yet available.