One firefighter injured fighting fire in East Boston Saturday night

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BOSTON — A firefighter hurt his back while working to knock down flames in East Boston Saturday night.

The fire broke out in a warehouse on Border Street - and although the cold temperatures didn't cause too many problems, they did have to be careful because they didn't know what was inside the building.

Fighting those tough conditions left one firefighter with a back injury.

Firefighters told Boston 25 News that it was initially difficult to locate the flames through all the smoke - and then, they found the building was a storage space for steel dumpsters.

They also had to use saws to cut through the metal roll up doors.

The cause of the fire is still under investigation.