INDIANAPOLIS (AP): Authorities say investigators don't believe criminal activity was involved in an explosion that blew part of the roof from an Indianapolis apartment building and burned two people.
 
       Fire Department Capt. Rita Reith says investigators are looking at possible accidental causes for the Thursday night explosion at the Pangea Riverside Apartments on the city's west side.
 
       Reith says a 20-year-old man and a 19-year-old woman remained hospitalized in good condition with burns from the explosion in their apartment. The building's 10 apartments are being kept off limits except for some residents being allowed to retrieve belonging.
 
       Residents told firefighters they smelled an odor like dirty water or sewer gas before the blast but couldn't find the source.