Boston's Big Dig tunnels used bolts glued with epoxy to hang the heavy roof panels that hung over the roadway. The epoxy failed catastrophically and the panel

Boston's Big Dig tunnels used bolts glued with epoxy to hang the heavy roof panels that hung over the roadway. The epoxy failed catastrophically and the panels fell on a car, killing the driver. Analysis of the accident blamed the workers who installed the bolts, but I think the big lesson is that construction sites are messy, and don't provide the best environment for the delicate chemical reactions needed to set adhesives properly.