WRIGHTSVILLE, Pa. (KDKA/AP) – Authorities say a Pennsylvania bridge has been closed for a second straight night because of swarms of mayflies so thick that they caused accidents.

Wrightsville fire officials say the Route 462 bridge over the Susquehanna River between Columbia and Wrightsville was closed Sunday night.

Chief Chad Livelsberger says a vehicle slowing because of the insects caused a crash, though he doesn’t believe anyone was seriously hurt.

The bridge was also closed Saturday night after three motorcycle crashes attributed to the flies.

Livelsberger says the department was dispatched to deal with one crash and saw two more crashes while on the scene.

YouTube video uploaded by a local fire department shows swarms buzzing around as first responders arrive on the covered bridge.

Mayflies are attracted by light and congregate on roads, bridges and other surfaces. When cars hit them, the females’ eggs release liquid that makes roads slick.

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