BOSTON (CBS) – One day after filing a wrongful death lawsuit, the family of a Blackstone man killed in a Norfolk house explosion met with the media.

Billy Nichols was working as an electrician at a newly constructed condominium last July when a propane tank leaked, leading to the explosion that killed him.

Billy Nichols

WBZ Radio’s Carl Stevens reports

Work crews never detected the leak in the basement because the strong chemical smell had faded.

Now his family is suing two local companies.

The lawsuit alleges the propane distributor, EnergyUSA, under-filled the tank, causing the odor to fade.

They also accuse Smolinsky Brothers Plumbing and Heating of improperly connecting the propane tank to the furnace leading to the leak.

They’re seeking unspecified damages.

WBZ-TV’s Alana Gomez reports

Nichols’ fiance Jill Cromwell was asked about her loss at a news conference in Boston Wednesday.

“How do you describe when you lose your world? How do you tell everyone you lost your everything? How can you describe that? Literally, I don’t feel like getting up in the morning. They took my world.”

Cromwell dated Billy Nichols for 11 years. They were engaged just months before the explosion.

Nichols’ brother Mark called the blast “an irresponsible, preventable accident.”

“We just want to make sure nobody else has to go through what we have for the last five months,” he said.

“They basically let a time bomb sit in that tank for three months. It was a formula for disaster,” said Marc Breakstone, the Nichols family lawyer.

EnergyUSA, based in Taunton, issued a statement saying, although they acknowledge the blast was because of a leak, the equipment they provided had all been tested and did not contribute to the explosion.

There has been no comment yet from Smolinsky Brothers.