The Brooklyn Bridge—one of the oldest suspension bridges in the US—stretches over the East River from Manhattan to Brooklyn. It was the first steel-wire suspension bridge in the world and, at the time of its completion, was the world's longest suspension bridge. Construction was plagued by at least 27 fatal accidents, one of which killed John A. Roebling, the bridge's designer. Days after the bridge opened, rumors of its impending collapse caused a stampede that killed how many people?