JOLIET, Ill. (CBS) — A massive explosion leveled a house in Joliet Sunday afternoon, and the blast was felt blocks away.

As CBS 2’s Steven Graves reported, perfect timing saved the lives of the couple who lived in the house.

Late Sunday night, crews were digging up a gas line, trying to figure out the cause of the explosion. The good news is all the victims were expected to survive, but neighbors called the destruction devastating.

“It’s gone – gone!” said one man said. “I mean, it’s leveled to the foundation.”

The explosion happened around 3 p.m. near East Washington Street and Argyle Avenue. Afterward, a part of the neighborhood resembled the sights and sounds of a war zone.

“Like when I was in Vietnam, that’s how it sounded,” the man said.

A young man who lives nearby told Graves he was playing video games when the explosion shook him off his bed.

“There was a huge bang outside, so I went out to look, and I see a big cloud of dust outside. It was really scary. I thought it was a firework at first, but it really shook the house,” said one young man who lives nearby I ran outside, because I didn’t know if a branch hit our house or something, so I contacted my family.”

There was panic from some on East Washington Street, who just went through rough storms and power outages last week. Now, the blast left their neighbors hurt.

“They’re good people,” said Michael Gambosi.

The blast busted glass windows on Gambosi’s home. Debris ended up in tree branches and on his roof.

But through the chaos, the focus was on helping the victims. One neighbor was hurt by debris, and the man and woman who lived in the home were also injured.

The husband was able to walk to an ambulance, while the wife was in worse condition, but alive.

“They got to her – had a few cuts on her head and cuts on her arms, but they asked her her name. She knew her name,” Gambosi said.

It was unknown late Sunday how the explosion happened. East Joliet fire investigators combed through loads of rubble late Sunday as Nicor gas crews worked beside them.

Neighbors said the couple had lived in the house for years, and now, decades of memories are gone.

“I’m just glad they’re alive,” Gambosi said. “I mean, that’s the main thing.”

The fire chief said the couple was outside of the home doing yard work when the house exploded, and that most likely saved their lives.