A massive former military hangar that burned in Tustin earlier this week, closing schools over asbestos worries, reignited Saturday night.

The city of Tustin tweeted that there was “an active flare-up above the north doors of the north hangar” around 5 p.m. Saturday, adding that the Orange County Fire Authority and the Tustin Fire Department were on scene.

The north hangar was one of two enormous structures on the property, 17 stories high and 1,000 feet long, that were used by the military during World War II and later served as sets for the TV show “Star Trek” and the film “Pearl Harbor.”

One of those hangars burned last week, creating a spectacle for drivers passing by.

After air quality experts discovered asbestos at the site, the Tustin Unified School District closed all campuses on Thursday and Friday.

The city also closed several public parks and canceled a planned Veterans Day celebration over health concerns stemming from possible contamination.

A note on the Tustin Unified School District’s website on Saturday said that Monday will be a “non-student day” on all campuses and that an environmental consulting firm has been retained to test all schools for contamination stemming from the fire.