Gunpowder? Yes! Treason & Plot? Er...No.

Macclesfield Bridge. Not in Macclesfield, but over the Regent's Canal in London.
In the early hours of October 10, 1874, the barge "Tilbury" was third in a train of vessels being towed by steam tug, laden with sugar, nuts, petroleum & 5 tons of gunpowder. The gunpowder caught fire, causing a huge explosion as the barge went under the bridge. The crew were killed, the bridge destroyed & windows shattered a mile away. The house of the artist Lawrence Alma-Tadema was also destroyed, although luckily for him he was not home.The Horse Guards were deployed to keep order & ensure safety from wild animals from Regent's Park Zoo.
The canal was closed for 4 days, but the cast iron columns survived the blast, & the bridge was re-built. It became known as "the blow-up bridge".