The 140-page report, dated Nov. 6 but released yesterday by the Department of Telecommunications and Energy, stops short of saying the alleged violations caused the explosion that killed 4-year-old Iris Carey and 5-year-old Violet Carey on July 24, 2002.

In the report, the DTE said NStar had no records to demonstrate that the service line segments installed in 1974 and 1979 were tested to set a maximum allowable operating pressure, or MAOP.

Because of that, the report said NStar may have violated a requirement that the line be tested at 1 1/2 times the MAOP.

In addition, NStar did not monitor the steel service line in the basement of the building for corrosion in the five-year period prior to the explosion. All exposed lines are required by state law to be tested every three years.

The report also states NStar did not perform leakage surveys of its service lines, which are required at least once a year.

NStar yesterday disputed the DTE's report.

"We strongly disagree with the findings of the new DTE staff report," said NStar spokesman Mike Durand. "The DTE previously conducted a comprehensive investigation with the state fire marshal's office and the state's independent safety expert.

"That report, issued in September, concludes our equipment operated properly," said Durand. "We are dismayed there is no reference to that conclusion in this new report."

Iris and Violet Carey's parents, Tara and Heath Carey, declined to comment yesterday. Their attorneys, Edward M. Swartz and Alan L. Cantor, issued a statement about the report.

"The report suggests that NStar failed to comply with basic safety requirements in connection with the gas service at 65 Main St., Hopkinton. Our clients have asked us to fully explore the deficiencies in NStar's systems so that other tragedies like this one can be avoided."

The Careys and their attorneys were scheduled to hold a press conference this morning at 10 a.m. at the Swartz and Swartz law firm at 10 Marshall St., Boston.

Iris and Violet Carey died when an explosion ripped apart the three-story apartment building at 65 Main St. on July 24, 2002. Ten other people in the building survived.

The blast leveled the building, injuring most residents and trapping Tara and Heath Carey and the couple's two daughters in the rubble.

Rescue workers quickly pulled Tara and Heath Carey to safety, but the two girls did not survive.

The DTE has proposed NStar agree to a consent order to pay a state penalty of $200,000 and make a number of procedural changes intended to ensure the company tracks down potential leaks.

Durand said the company will not agree to the order.

"We fully intend to appeal the DTE staff report to the full (DTE) commission," he said.

The report also includes written statements from all the residents of the building.

Tara Carey described her experiences after she went to bed at 11 p.m on July 23, 2002.

"The next thing I recall is seeing an orange and blue flash and feeling intense heat," she wrote. "I felt myself subsequent to that time trapped under a significant amount of debris and was having difficulty breathing.

"I could feel the face of one of my children and attempted to wipe debris from their face in order to create an air pocket," she continued. "At some point subsequent to that, Heath managed to free himself of the debris and moved enough of the debris from my body allowing me to follow him in exiting the building."

Janet Webster, who lived in the building, said she evacuated her family after she heard a loud noise and went to the basement and smelled a strong order of gas.

"We left the house, I called 911 on my cell phone as we were walking out of the driveway," she wrote in the report. "First, I pulled into Colella's parking lot. The Hopkinton Fire Department told me to meet them in front of the house. I pulled over across the street and before I hung up the cell phone and shut off my car the house exploded."

Another resident, Richard Mays, also said he heard the noise, and was ready to leave the house when the explosion happened.

"As I was about to walk back to my bedroom, the house exploded," Mays said. "I was lifted up. The room got pitch dark with red sparks flying over my head. A split second later I went down with the floor, hearing the wood squeak. My thought was,'This is it.'"

The Carey family has filed a $50 million wrongful death suit against NStar, their landlord and Holden-based pipe fitting manufacturer Inner-Tite Corp., claiming a faulty natural gas fitting was behind the explosion. That case is pending.