Sometime during the morning of Sunday, February 7, 1904, a smoldering fire burst into flame in the basement of the John Hurst & Company, a dry goods store located at Hopkins Place, near the present-day Baltimore Arena.

It’s thought that a carelessly discarded cigar or cigarette fell through a broken 2-inch glass block window in the sidewalk that served as skylight for the Hurst basement.

The first alarm was rung at 10:48 a.m. Within minutes the roof of the Hurst building was ripped off in an explosion, spewing a fountain of burning embers and debris into the southeastern breeze. Four more buildings were set aflame.

Fire chief George Horton, arriving just after 11, recognized the enormity of the situation and called almost the entire Baltimore City Fire Department. Eight hook & ladder trucks and 24 engines responded to the growing conflagration downtown.

Shortly after noon, Horton sent an telegram to the Washington, DC, fire department: “Desperate fire here. Must send help at once.”

Firefighters and their equipment sped by train from Washington, arriving in less than an hour. But they couldn’t connect their hoses to the Baltimore fire hydrants. The couplings didn’t fit.

Urgent calls for assistance went out to cities and communities across the region as the fire tore through the heart of the city’s business and financial district, devouring brokerages, factories, banks, and law offices in its path.

Around 5 p.m. On Sunday, as the fire marched relentlessly to the east and south, engineers decided to dynamite buildings in a misguided effort to create a firebreak to halt the progress of the flames.

Buildings at Charles and Redwood (then called German Street) were blown up with hundreds of pounds of dynamite, which blew out supports but left the buildings standing.

The effort failed to create a firebreak, and left the buildings precariously unstable. Windows in nearby buildings were shattered by the blasts, more effectively spreading the flames.

Over the next day, firefighters arrived from Philadelphia, Wilmington, Frederick, Westminster, York, Altoona, and elsewhere. A special train was dispatched from New York City with eleven engines and their crews.

In all, 1,231 firefighters battled the inferno – many of them unable to connect the fire hoses they brought to the city’s hydrants.

The fire spread through the center of downtown for 30 hours, stopped by the harbor to the south and the Jones Falls to the east, before being brought under control late Monday afternoon. The rubble smoldered for weeks.

Seventy city blocks, an area of about 140 acres, had been laid to ruin. More than 1,500 buildings were destroyed, displacing about 2,500 businesses the phone company, four newspapers, the post office and custom house, Western Union, several banks and many factories.

Baltimore used the catastrophe to redesign and improve downtown – widening and straightening streets, enacting new fire codes, taming the Jones Falls once and for all, and finally getting rid of the open sewers. Baltimore was the last major American city to have an enclosed sewer system.

“We shall make the fire of 1904 a landmark not of decline but of progress,” Mayor Robert McLane told a Baltimore News reporter.

Nationally, the disaster brought into focus the lack of standards in firefighting equipment.

At the time, the National Bureau of Standards estimated that there were more than 600 different sizes and variations in fire hose couplings across the country. Manufacturers used the variations as a competitive advantage, making it difficult for fire companies to switch vendors.

The issue was brought home to the National Bureau of Standards later in 1904 when employee Franklin Durston, while trying to put out a small fire, discovered that the hose couplings from the bureau’s north building were incompatible with those from the south building.

In 1905, a committee of the National Fire Protection Association established a national standard diameter and threads per inch for hose couplings and fire hydrants. The 1905 NFPA standard specifies that fire hydrants have 2.5-inch hose connections with 7.5 threads per inch, and 4.5-inch pumper connections with 4 threads per inch.

It was – and still is – known as the Baltimore standard, and remains the national standard for fire hose couplings to this day.