SANTA ANA (CBSLA) — A 4-alarm fire tore through a vacant church in Santa Ana early Thursday morning.

The fire broke out at about 2:25 a.m. Thursday in the 100 block of East Santa Ana Boulevard, near Main Street. Crews who arrived at the scene first found flames going through the roof of the church and immediately upgraded the incident to a third-alarm structure fire.

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The fire was ultimately upgraded to a four-alarm emergency. Video posted by the OC Fire Authority showed  flames shooting high into the sky, and burning embers falling from the roof of the church.

The fire was declared just after 4:30 a.m.

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The cause of the fire is under investigation. Firefighters say they’ve had reports of homeless people living there in the past.

No injuries were reported.

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The building, which was built in 1911, formerly housed the United Presbyterian Church and was later home to Templo Calvario and the Orange County Pacific Symphony. It is listed on both the national and California registers.