On Sept. 17, 1862, 78 people - 71 young women and 7 men - died when the Allegheny Arsenal in the Lawrenceville neighborhood of Pittsburgh exploded. This was the largest single day civilian death toll of the Civil War, but it was overshadowed because of events that happened in Sharpsburg, Maryland at The Battle of Antietam.
Thomas Taber Museum, It's History! Pennsylvania's Neighborhood: Williamsport
Ben Franklin: An American Life, PA Books
Kuechler's Roost, History & Culture