The cause of a fast-moving five-alarm fire, which ripped through multiple business in the Bronx on Tuesday morning, is now under investigation.

The FDNY said 250 firefighters responded to the call that came in around 5:30 a.m. in a commercial building on East 194th Street in Fordham Manor. The blaze ended up destroying six stores on the strip of businesses.

The FDNY had advised people in the neighborhood in the morning to keep their windows closed due to heavy smoke.

Officials said the fire department got the fire under control in about four hours.

Fire officials said they were just thankful nobody was injured or killed.

"Biggest challenge is to make sure we don't get hurt on this type of building in the morning with the smoke. We had to make sure that we protected the apartment building behind you, as you see, from not only fire, from smoke, and to make sure all of those people get out, which they did," FDNY Chief of Department James Leonard said on-scene.

As of Tuesday night, it was not confirmed where or how the fire began.