(WHTM) — Around noon on February 7, 1904, Baltimore firefighters responded to a fire call at the John E. Hurst and Company on West German Street. As the firefighters tried to enter the burning building, an explosion shot embers through the building’s broken windows and onto nearby structures.

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The Great Baltimore Fire had begun.

Winds out of the south and southwest quickly pushed the fire north and east, engulfing many of the blocks around what’s now know as Inner Harbor. City officials realized they didn’t have enough firefighters to cope with the blaze, and put out the call for help.

Help came from all directions, including central Pennsylvania. Fire companies from York and Harrisburg joined units from Washington, Philadelphia, New York, Wilmington, Frederick, Westminster, Chester and Altoona who answered the call. Baltimore had an army of 1,231 firefighters to battle the inferno, Most of these squads brought along their own firefighting equipment and engines to help.

And a lot of that gear proved to be utterly useless.

There were, at that time, no standards for firefighting equipment. Many of the hoses crews brought to help fight the fire wouldn’t connect to the Baltimore fire hydrants. Firefighters were forced to watch helplessly, as the fire surged onwards

By the time it was finally contained, almost 30 hours later, it had leveled 140 acres, stretching over 70 city blocks, of downtown Baltimore. Over 1,500 buildings were destroyed, displacing about 2,500 businesses. Miraculously, there were few if any deaths. (There’s dispute on this matter.)

Baltimore rebuilt, of course, redesigning the downtown area with wider and straighter streets-and beefed up fire codes.

Nationwide, the fire spurred an effort to standardize firefighting equipment. The National Bureau of Standards estimated that across the country there were more than 600 different sizes and variations in fire hose couplings. (The Bureau of Standards itself had this problem-they learned the hose couplings in their north and south buildings were incompatible.)

In 1905, The National Fire Protection Association established some national standards. They call for fire hydrants with 2.5-inch hose connections with 7.5 threads per inch, and 4.5-inch pumper connections with 4 threads per inch. This has become known as the Baltimore standard. It remains the national standard for fire hose couplings to this day.