Updated at 10:46 p.m. ET: The huge explosion that flattened homes and killed two people on Nov. 10 in Indianapolis is now being investigated as a homicide case, authorities said at a press conference Monday night.
Marion County Prosecutor Terry Curry appealed to the public for information about a white van that was seen in the area, NBC affiliate WTHR reported. He said the federal Bureau of Alcohol, Tobacco, Firearms and Explosives is assisting with the case.
"While the fire investigation has been progressing, there has been a parallel investigation, not solely focusing on the cause of the explosion but focusing on individuals who may have been responsible once accidental causes were eliminated," Curry said. "That investigation has consisted of numerous interviews with various individuals as well as execution of a number of search."
The interviews and search warrants are why the investigation is considered an active criminal homicide investigation, Curry said.
Jennifer Longworth, 36, and Dion Longworth, 34, were killed when their house collapsed on them. The couple lived next door to the house where the explosion happened.
Eighty-one homes out of 125 in the subdivision were also damaged, according to the Indianapolis Star. More than half the homes were deemed unsafe and the city asked that they be boarded up by the end of the day on Monday.
The blast originated in the house of Monserrate Shirley, a 47-year-old nurse. Shirley was out of town at a casino with her boyfriend when the blast occurred, authorities said. Her 12-year-old daughter was staying with friends. Their cat had been boarded before the blast, according to the Star.
In a tearful interview with the Star, Shirley said: “I’m devastated. I don’t sleep. I don’t eat. I’m just shocked like everybody else. It’s like waking up to this bad dream. I mean I wish I was there, I would be dead. I wouldn’t need to be asked any questions.”
Monday's announcement came hours after the funeral service for the Longworths.
Southwest Elementary, where Jennifer Longworth worked as a second-grade teacher, was closed Monday so students and teachers could attend the service. The funeral took place at St. Barnabas Catholic Church, where the Longworths were married 11 years ago, according to the Star.
Meanwhile, some 20 firefighters and police officers carefully and slowly combed the blast site, hunting for clues in the debris.
Crimestoppers is offering a $1,000 reward for information leading to an arrest. The ATF promises a $10,000 reward leading to an arrest and conviction.
NBC's Isolde Raftery contributed to this report.
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