Crews are investigating a manhole explosion near the Conrad Hotel in downtown Indianapolis. Firefighters and Indianapolis Power & Light officials say the explosion occurred shortly after 6 a.m. Wednesday. People inside the Conrad Hotel heard a loud explosion behind the building in an alley. The manhole cover was blown off and a small fire was visible inside the manhole. During the cleanup, Meridian Street was closed between Washington Street and Monument Circle. IPL said manhole explosions are a “rare occurance” and downtown residents shouldn’t be concerned.