Crews continue to investigate what may have set off an explosion that flattened a house in Coon Rapids.

The Anoka County Fire Investigation Team and the State Fire Marshal spent hours on scene again Thursday.

The house on the 800 block of 104th Avenue Northwest blew up around 3 p.m. Wednesday, according to the Coon Rapids Fire Chief.

One man was seriously hurt in the blast.

Neighbors spent Thursday cleaning up debris — including shattered glass, insulation and siding that had blown off the house.

“The house across the street from me blew up. That’s not a sentence you think you get to say for real,” said Jon Puffer, who lives across the street. “It’s absolutely crazy.”

Jon and Patti Puffer live directly across the street.

They showed 5 EYEWITNESS NEWS photos of their neighbor’s garage door that had flown all the way across the street into their home.

“It had to fly over our cars essentially to not damage the cars but still come in and hit the garage door this hard,” Jon Puffer said.

Patti Puffer, a former EMT, said they ran outside after the explosion Wednesday and spotted a man walking out of the leveled house.

“I couldn’t believe he was alive,” Patti Puffer said. “He had burns just everywhere. His clothes were singed. His hair was singed. He was scared and confused. I was holding a towel on his head because he was bleeding profusely from lacerations.”

Investigators are still trying to determine what caused the explosion.

“He said he was trying to make something to eat and he heard the gas whistling and was running upstairs to turn it off,” Patti Puffer said.

The homes on either side of the explosion were badly damaged as well.

Mike Wright has lived in one of those homes for the past 41 years.

He told 5 EYEWITNESS NEWS he was inside his bedroom at the time of the blast and called 911.

“Of course they always ask you, ‘Is this an emergency?’ I said, ‘Yes, it’s an emergency.’ They said, ‘What’s your emergency?’ I said, ‘The house next door just blew up,'” Wright recalled.

A side wall of his home fell down in the force of the explosion.

Shortly after, the remnants of his neighbor’s home caught fire, with the flames spreading to his home as well.

He believes his house is destroyed, along with many of his belongings.

“There’s always keepsakes but, there again, life goes on. We got to deal with it,” Wright said. “It doesn’t do any good to bemoan the situation.”

Insurance adjusters walked through Wright’s home Thursday to assess the damage.

The Puffers plan to have the foundation of their home inspected as well, in the aftermath of the explosion.

“This is obviously going to be a big long process to fix,” Patti Puffer said.