(CNN) -- The explosion that killed two people and hurt seven in an Indianapolis subdivision is now the subject of a criminal homicide probe, authorities announced Monday.
Police want to know about a white van seen in the neighborhood before the November 10 blast that leveled several homes, Marion County Prosecutor Terry Curry said. Neither Curry nor other investigators released any more details on the matter, saying only that a "parallel investigation" had been going on while they were seeking the cause of the explosion.
The late-night blast destroyed several homes and severely damaged more than 30, firefighters said. At one point, 60 to 70 firefighters fought the resulting fires.