Black smoke rose from a construction site in Little Italy accompanied by an overwhelming smell of plastic Thursday.
San Diego Fire and Rescue crews responded to the call of a subterranian fire at 1907 Columbia Street near Fir Street around 11 a.m.
There are two levels beneath street level filled with rebar, construction equipment and pallets of materials.
Because of the intense smoke, flashlights were useless so firefighters had to use thermal imagers to pinpoint the location of the fire.
One firefighter suffered a bruised leg during a fall eight to 10 feet down an elevator shaft said San Diego Fire and Rescue spokesperson Maurice Luque.
It took about 30 minutes to locate the fire. Crews were using oxygen while underground and had to surface after several minutes to replace the bottle Luque said.
Firefighters did find a pallet stacked with electrical conduit that had caught fire. Fire investigators are looking into the cause of the fire.
Construction workers who were welding just before the fire immediately left the area once fire broke out, Luque said.
There was no threat to the site or any other buildings.
Construction crews are in the process of building the ground level of a condo complex.
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