As for the cause of the explosion in Pueblo on Thursday, the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) said they are not ruling anything out. They could be at the scene for days. What they are looking for are patterns similar to a gas explosion or a dynamite explosion.

They are also looking for residue or anything that would point to a direct cause into the horrendous explosion. ATF said they have also analyzed surveillance video of the actual explosion.

“Each explosive scene is different. The expertise that the investigators bring actually helps further the cause, but right now, we don't have a determination," said ATF Special Agent John Hageman.

Three businesses remain closed in the Pueblo Downtown Historic District. The rest of the stores are trying to get back to normal.

"There's a lot of people who don't know we're open," said Laurie Sole, owner of Daily Grind.

“We've been busy. They are shopping when they (the on-lookers) come downtown to see the scene," said Lindsay Bradshaw with “Gotcha Covered”, a gift shop across the street from the explosion.

“It could’ve been me,” said Arleen Podschweit. She hasn't been to the Pueblo Union District since Thursday after she finished up her shopping just minutes before the explosion.

"I think it's terrible. It’s terrible for this town," said Peter Michaelis, who is visiting Pueblo from Germany.

State Representative Buffie McFayden told 11 News that since this is a busy time of year for the stores, if businesses start to suffer, the shops may get financial help from the state.