BALTIMORE (WJZ)– We’re hearing the 911 calls from the moments after a five-alarm fire ripped through a Fells Point warehouse.

Mike Schuh reports with a look at the emergency response.

The first caller is almost apologetic.

911 Caller: “I’m not sure if this is an emergency yet.”

But soon, there is no doubt.

911 Caller: “But then the smoke is getting heavier and thicker. Now I wonder if it could possibly be a fire.”

With that, the calls flood in.

911 Caller: “And this building just started exploding. I saw fire and black smoke coming out of the windows.”

911 Caller: “Oh, they got smoke coming from the building on Eastern Avenue, the corner of Eastern Avenue and Broadway.”

911 Caller: “Oh yeah, black smoke all over Eastern Avenue. It’s like thick.”

Report of a building fire at the rear of Save A Lot. Now, over 100 firefighters begin to arrive from all directions.

911 Caller: “Looks like there’s a police helicopter overhead so it looks like they must be aware of it. I am in my residence adjacent to the building.”

Firefighters note they can’t get into the building from the front, and have to break in.

“Engine 5 to Truck 3. I need your saw down here, I need to open this metal door.”

This grows big enough that it takes firefighters over four hours to douse the flames.

In the process, one firefighter in a bucket truck hurts his foot, but otherwise there are no injuries. But the building is destroyed.

Fire investigators tell WJZ that they are still trying to determine the cause.