Authorities have closed a number of intersections downtown and evacuated people nearby, after an explosion under First and Main streets this morning.Officials are telling WLKY that the explosion was apparently caused by a transformer malfunction.The surrounding area has been evacuated and nearby streets have been closed. Traffic is being routed around First and Main, and a number of other intersections are closed, including First and Market, Second and Market, and Third and Market.Traffic lights aren't working at some intersections near the site of the explosion and fire, and dozens of businesses in the area have been affected by scattered power outages.More details as we get them.