Officials said both explosions likely were caused by heavy rains and later freezing and thawing that triggered a series of short circuits in underground utility lines.

Are the standard strand of Christmas lights connected in series or parallel? What's the difference between series and parallel anyway?

INDIANAPOLIS (AP) -- An underground explosion injured three people Saturday and forced authorities to evacuate dozens of residents from a downtown condominium.

Officials said both explosions likely were caused by heavy rains and later freezing and thawing that triggered a series of short circuits in underground utility lines.