MIDDLETOWN, Conn. (AP) — The widow of a pipefitter who died with five colleagues in a Connecticut power plant blast urged federal officials Monday to tighten safety rules for cleaning industrial pipes.

Jodi Thomas' plea to members of a congressional subcommittee came as its members and a separate federal safety board consider asking regulators to ban a procedure that uses explosive gas to clean pipes, a practice that led to deadly blasts in Connecticut and North Carolina.

Thomas' husband, Ron Crabb, was one of six people killed in the blast at the Kleen Energy Systems power plant in Middletown in February. In June 2009, four people died and nearly 70 were injured at the ConAgra Slim Jim factory in Garner, N.C.

In both cases, natural gas accumulated during the pipe-cleaning procedure, known as a "gas blow," and ignited. Workplace safety groups say using air or nitrogen to purge pipes would be safer.

"This tragedy should never, ever have happened. It was preventable. This is why I urge you, please, do not allow Ron's death to be in vain," Thomas told members of the Workforce Protections Subcommittee of the U.S. House Education and Labor Committee at their hearing Monday in Middletown, a few miles from the blast site.

"Real change, real protection for hardworking Americans, must come out of this. It is the only way to truly honor him and the other men who lost their lives, whose families are forever broken," she said, her voice breaking slightly at times.

Crabb's brother, Carle, submitted written testimony blaming a lack of regulation and cost cutting for the blast. He recalled his brother's dog sitting on the ice of his driveway, waiting hours for his brother to come home.

"No man or woman should not be able to return to their home at the end of the work day," Carle Crabb said.

Middletown police and fire officials, state police and the U.S. Occupational Safety and Health Administration, are investigating the explosion. Middletown police have not yet determined whether any individuals or entities should face criminal charges.

U.S. Rep. Rosa DeLauro, D-Conn., promised Thomas an unspecified "legislative remedy," and said after Monday's hearing that she would support a ban on the gas-blow procedure.

Officials said the issue is urgent because there are plans for an additional 125 power plants in the country in the next five years.

"As unbelievable as it sounds, there is no law, regulation, standard or code, either in Connecticut or on the federal level, that directly regulates the 'gas blow' procedure in natural gas power plants," said Rep. Joseph Courtney, D-Conn.

Courtney said he was skeptical the industry would adopt voluntary consensus codes. Failing any action, he said Congress should move swiftly to protect workers from the procedure.

Experts said natural gas is still being used to clean pipes, apparently because it involves less money and time than alternate methods. Still, they called it "unfathomable" and "bizarre" that industry would spend more than $1 billion on a plant, only to risk blowing it up.

"It doesn't make any sense to me," said John Bresland, a member of U.S. Chemical Safety and Hazard Investigation Board.

O&G Industries Inc., which was involved in the gas blow, said Monday it supports the recommendations of the safety board, including using alternatives to natural gas for cleaning the gas piping. The company said its subcontractors will not use natural gas to clean the fuel gas piping during the rebuilding of the plant.

Later Monday, the safety board was expected to advise regulators to ban the practice, which it says has also caused other potentially deadly explosions.

The board was meeting in Portland, just across the Connecticut River from the Kleen Energy plant. It planned to vote on a series of recommendations for better oversight, licensing and alternatives to the gas-blow procedure.

"From a fire and explosion perspective, releasing large volumes of natural gas in the vicinity of workers or ignition sources is inherently unsafe," the safety board wrote in a report.

If approved, the board's recommendations would be sent to OSHA, the National Fire Protection Association and other organizations.

In prepared text released before the subcommittee hearing, Bresland said there is a "significant gap" in existing gas safety standards for general industry and construction that continues to threaten the safety of workers.

"The present patchwork of inadequate codes and voluntary practices does not protect America's workers from the kind of explosions that killed six at Kleen Energy, killed four at ConAgra and threatened many others with death or injury," he said.