As a lover of trivia and knowledge, maybe you’ve heard the fun fact that the original patent for the fire hydrant was destroyed in a fire. That’s true—but it was just one of thousands of patents that went up in smoke during an accident in 1836.

The United States Patent Office was located in a building formerly known as Blodgett’s Hotel, which the government purchased in 1810. The large building also housed the post office, and, amazingly, the fire department. The various tenants shared certain parts of the building, including the fuel room in the basement. Unfortunately, the post office stored smoldering ashes in an ember box in the fuel room, not far from where patent office employees stored firewood. On December 15, 1836 at 3 a.m., the smoldering ashes mingled with the firewood, and the building went up in flames.

Though the fire department’s close proximity should have helped, their only hose was more than 15 years old and hadn’t been well-maintained, rendering it almost useless. The whole building collapsed in less than 20 minutes, taking an estimated 9000 drawings and 7000 models with it, including Robert Fulton's model for the steamboat.

It wasn’t the first time the office had faced the threat of fire. When the British burned Washington in 1814, Patent Office Superintendent William Thornton managed to convince soldiers to spare his building; it was the only government office in D.C. that didn’t get torched. Sadly, everything he worked to save was destroyed 22 years later in the 1836 fire. Though Congress used private records and models to restore as many patents as possible, only 2845 of the roughly 10,000 patents in existence were reinstated. The remaining 7000+ patents and pending patents were voided.

The inferno changed the way the U.S. Patent Office did business, leading it to introduce a numbering system for better record-keeping and a policy of keeping copies of the patents elsewhere, among other things. The changes came in handy in 1877 when the office caught fire again, even though its new headquarters was specifically designed to be fireproof.

Wikimedia Commons, Library of Congress // Public Domain

Though more than 87,000 models were destroyed in the second fire, it’s said that no inventor lost a patent, due largely to the documentation measures implemented after the first fire.

Today, the headquarters of the U.S. Patent and Trademark Office is located in Alexandria, Virginia—and the office assures the public that its patents are much safer these days: “Duplicate copies, electronic databases, cross-references, and off-site storage of patent documents, now guarantee that an important part of America's history will never be lost again.”