Kitchener’s fire chief says officials may never be able to determine exactly what caused a southwest Kitchener house to explode last month.

On Jan. 27, a house at the corner of Activa Avenue and Isaiah Drive exploded, causing a fireball that lit up the night sky.

A family of four was home at the time. All four, who were in bed at the time of the blast, were taken to hospital – three released quickly while the family’s father, Minh Nguyen, underwent surgery in Hamilton for a broken pelvis.

Nguyen continues to recover from surgery in hospital.

The investigation into the explosion is now into its sixth week, and fire officials remain perplexed.

While they have been able to determine that the fire was gaseous in nature, investigators have had more luck at ruling out causes.

Natural gas or methane pockets, issues with gas supply lines, criminal activity and defective appliances have all been discarded as possibilities.

“At the end of the day, if we can’t rule out certain events or certain possible events, then the cause would go down as undetermined,” Kitchener Fire chief Tim Beckett tells CTV.

“We’re not there as of yet.”

The Centre of Forensic Science is still testing material recovered from the explosion site, a process which could take months.

If those tests prove inconclusive, the cause of the blast may never be officially determined.

Neighbour Geoff Roberts says he’d be disappointed not to know what caused the explosion.

“If they safe everything else is safe and this was just an isolated incident then sure, put it behind us and hopefully the family does rebuild and go on,” he says.

The Kitchener Fire Department held a public meeting last week to answer questions from neighbourhood and ease concerns.

Kitchener city councillor Kelly Galloway-Sealock attended the meeting. She says she’d like to see the city do more to help eliminate fears over natural gas.

“That may be something like natural gas detectors, starting a program with that, whether we give them out for free or what we do with that, that’s one option,” she says.

Also suggested at city council was assisting homeowners with natural gas inspections.