It was empty at the time of the blast, but a spark ignited a buildup of natural gas vapors, causing an explosion that caused a second barge to catch fire, CNN affiliate WALA TV reported, citing Coast Guard Lt.

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Last August a gas leak at the Amuay refinery in western Venezuela led to an explosion and fire that burned for days and killed more than 40.

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Investigators are trying to determine whether the explosion was gas-related, said Robert Kuehn, an inspector for the Brentwood Fire Department.

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