Nightmarish 'Mayfly Blizzard' Closes Bridge For 2 Nights, Causes CrashesAuthorities say a Pennsylvania bridge has been closed for a second straight night because of swarms of mayflies so thick that they caused accidents.
Mayflies Invade Pittsburgh's North ShoreMayflies are back again – this time at PNC Park on Pittsburgh’s North Shore.

More From CBS Pittsburgh

New Podcast Network
Learn How
Get The All New CBS Local App

Listen Live