Officials shut down the Veterans Memorial Bridge between Columbia and Wrightsville for about 45 minutes shortly after 10 p.m. Sunday. 

It was reopened shortly before 11 p.m., a Lancaster County-Wide Communications supervisor said. 

It was the second night in a row the bridge was closed. The cause, both times, was swarms of mayflies. 

WATCH: 'Blizzard' of mayflies swarm Route 462 bridge

On Saturday night, they caused three motorcycle crashes due to poor visibility as well as slick conditions resulting from dead mayflies covering the roadway.