A West Long Beach storage facility sustained extensive damage Tuesday morning following a second-alarm fire, authorities said.

The fire began sometime around 5:52 a.m. in the 1000 block of West Carson Street and was originally thought to be a brush fire, officials said. But when Long Beach firefighters arrived, they saw smoke emanating from the eastern part of the large storage facility building. Eventually, at least 30 fire units became involved in an offensive attack to stop the blaze, updating the incident to a second alarm, LBFD spokesperson Brian Fisk said.

After the second floor collapsed in one of the affected areas, fire personnel transitioned to a defensive strategy, using the ladder pipe to extinguish the blaze from above, fire officials said.

The bulk of the fire has been knocked down and units are completing an overhaul operation to ensure there is no smoldering, officials said. No injuries were reported.

Arson investigators also responded to the scene and the cause of the fire is being investigated.

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