Benjamin Henry Latrobe, much more famous for his work on the United States Capitol, was Pittsburgh’s first resident professional architect. This is his only remaining work here, and the only original 1814 building left from the Allegheny Arsenal.

This plaque was originally on the gatehouse to the Arsenal grounds.

A memorial put up by the Daughters of 1812 appears to have had a bronze relief, probably stolen many years ago.

The Arsenal is most famous in history for exploding during the Civil War, killing dozens of the workers, many of whom were children. We note that the building where the powder was stored did not explode—an indication, perhaps, that the architect knew his business.

DESIGNED BY BENJAMIN H. LATROBE; BUILT BY CAPTAIN ABRAM R. WOOLLEY ON LAND PURCHASED BY THE FEDERAL GOVERNMENT FROM WILLIAM B. FOSTER. SERVED AS AMMUNITION PRODUCTION CENTER DURING INDIAN, MEXICAN AND CIVIL WARS. THIS TABLET COMMEMORATES AT LEAST 79 CIVILIAN WORKERS—MEN, WOMEN AND MANY CHILDREN—KILLED IN THREE MYSTERIOUS EXPLOSIONS, SEPTEMBER 17, 1862.

Old Pa Pitt would add that the explosions were not as mysterious as all that. It was an arsenal. The place was devoted to manufacturing things that explode, using explosive materials. Everyone knew that Dupont & Co. had been supplying powder in leaky barrels, probably reused in spite of the specific requirement not to reuse them. Everyone knew there was explosive stuff dusting the ground here and there. The only mystery was which of several possible causes set off the first spark, and that mystery will probably never be solved.

The remains of the dead were buried in a mass grave in Allegheny Cemetery, where an expensive marble memorial was put up. The marble eroded into illegibility by the 1920s, and it was replaced with a new monument with a bronze plaque that will last a few more centuries if it is not stolen and melted down.

Today the powder magazine sits in the middle of a pleasant urban oasis called Arsenal Park. Instead of explosive materials, it has rest rooms.