Ronald and Stacy Oliveira were in their Acushnet home, asleep with four children in the house, when the fire woke them up early one January morning in 2008. They ran out of the house with nothing but the clothes they were wearing.

“The house was fully engaged in every room and every level of the house. You could hear the roof collapsing and you could see the fire in all the front windows. You knew that it was going to be impossible to save anything,” Ronald Oliveira said.

“We were lucky to get out of there alive,” Stacy Oliveira said.

The minute fire crews arrived, they could tell something was different about that fire.

“We had a hellish scene,” said Acushnet Fire Chief Kevin Gallagher.

Gallagher says the home had working smoke detectors, but the fire spread so quickly, they didn’t go off until the family was outside.

“If they had slept deeper, if they didn’t pay attention like they did, then we would probably have had six fatalities,” he said.

The cause of the fire was a discarded cigarette butt. But that didn’t explain the size and speed of the blaze. That explanation lay in a huge empty space between the first and second floors, 20 inches high and as wide as the home itself. Firefighters call it a void space.

When a fire enters a void space, Gallagher said, “It travels. It spreads. We don’t know where it is.”

That void space is a common feature of modular homes, which are built in pieces in a factory then assembled at the homeowner’s site. But the chief found more that troubled him.

Like other modular homes, the ceilings in the Acushnet home were attached with a highly flammable foam adhesive. That adhesive is similar to the foam that ignited during the infamous 2003 Station nightclub fire.

Gallagher lit a sample of the adhesive used in a modular home on fire, and watched as it rapidly ignited and became completely consumed by fire.

“If it is ignited, it is going to burn. It’s going to burn fast. It’s going to burn hot,” he said.

That burning glue is another reason why Gallagher believes the fire consumed the Acushnet home so quickly .

“Once the fire gets into the void space, it destroys that glue. It’s just going to drop the ceiling. And in this case, that’s what we believe contributed to the spread of this fire,” he said.

But the Acushnet home isn’t the only one with that void space or flammable adhesive. Almost all modular homes have them. As he investigated the fire, Gallagher began to wonder if the same thing would happen to other modular homes if a fire started.

“My sense is that this is a bigger problem than we’re aware of,” he said.

Just six months after the Acushnet fire, flames consumed a modular home in Hanson.

Gallagher began to push for changes to the state building code.

The state doesn’t track how many modular homes have been built in Massachusetts since they came into existence decades ago, but since electronic record-keeping began in 2003, 1,608 have been built here, state records show.

Overseeing that state building code is Thomas Gatzunis, commissioner of the Massachusetts Department of Public Safety. He said he’d have no problems living in a modular home.

“Massachusetts has one of the strongest building codes in the country when it comes to fire safety issues,” he said.

So far, Gatzunis says Massachusetts has no plans on changing its building codes regarding modular homes. But he does say he’s concerned that the flammable foam adhesive has been overused in some homes.

He was concerned enough to warn modular home builders in an e-mail last May to “control the excessive use of adhesives.” If local building inspectors find too much of the foam adhesive sprayed on, Gatzunis says he wants the homes shipped back.

He acknowledged, however, that there is no way to tell how much overspray may already be in existing modular homes.

“There is not, no. Not without doing destructive testing, removing ceilings, removing floors. There is no way to determine that,” he said.

Destructive testing is just what Ron Chasse had done in his modular home in West Boylston. He opened up ceilings and walls to try and resolve a dispute with his modular home builder. He was shocked to find the flammable adhesive applied far heavier than the small bead recommended by the manufacturer.

“There’s absolutely no need of using foam seal like that,” he said, pointing to framing members inside his home that were covered with the foam adhesive.

“A lot of people need to be concerned. You need to be concerned about what lies underneath the walls of their modular home,” he said.

So are modular homes less safe than traditional, or so-called stick built homes?

“As far as I know, no one knows the answer to that now,”