Mayflies Swarm Causes Bridge Closure

A swarm of mayflies had become so large and dense, authorities in Lancaster County, Pennsylvania decided to shut down the Route 462 bridge between Columbia and Wrightsville on Saturday night. According to the government, three motorcycle crashes occurred because of the flies. The swarm was so thick that as the mayflies flocked to the lights on the bridge and died, they made piles several inches deep of dead mayflies.