The families allege the women were unaware of a faulty water heater that pumped carbon monoxide into their suite, ultimately causing their deaths.

From left, Kaoutar Naqqad, Wafae El Arar, Imane Mallah.Obtained by NBC News

The families of three Massachusetts women who died at a Belize resort last year have filed a wrongful death lawsuit against the hotel they were staying in.

The women - Wafae El-Arar, 26, Kaoutar, Naqqad, 23, and Imane Mallah, 24 - died from carbon monoxide poisoning while they were staying at the Royal Kahal Beach Resort last February, their families said a month after their deaths. The U.S. Embassy in Belize confirmed the deaths were due to carbon monoxide poisoning.

Now, the Royal Kahal Beach Resort is listed among a number of defendants in the wrongful death suit, filed in the U.S. District Court in Massachusetts on Tuesday.

NBC News has reached out to the Royal Kahal Beach Resort for comment on the situation and the lawsuit.

Louis J. Muggeo, one of the lawyers representing the plaintiffs, said the basic premise of the case is that "these young girls who suffered tragic painful deaths - it was a preventable death."

"The resort and developers cut corners by employing incompetent installers to put in these hot water heaters," Muggeo added. He said the hotel failed to take "appropriate remedial measures" and as a result the three young girls "died tragically."

"It was preventable. It never should have happened," he said.

The suit alleges "wrongful death, conscious pain and suffering, punitive damages, and product liability" over the "preventable death" of the three women, court documents state.

The deaths were the direct result of "a catastrophic failure of safety systems," including failing to install the water heater properly, failing to investigate prior reports of other guests who reported symptoms of carbon monoxide exposure, and failing to provide functional carbon monoxide detectors in the guest suites, the women`s families allege in the lawsuit.

According to the suit, the women booked their trip to Belize in early 2025 to celebrate one of the women`s birthdays. At the time of booking, the women were unaware of the dysfunctional heaters at the resort.

When the women turned the shower on after a beach day on February 20, 2025, the suit alleges that it activated a hot water heater that "began venting high concentrations of carbon monoxide directly into the suite."

"The three women were unaware of the danger" of the carbon monoxide, according to the lawsuit. "They were overcome by the toxic gas and are believed to have died during the night of February 20, 2025, having suffered excruciating conscious pain and no doubt realizing they were dying."

Their bodies were discovered around noon two days later by resort staff. The lawsuit states that the autopsies for all three women confirmed they died due to carbon monoxide poisoning.

"An investigation revealed lethal toxicity levels inside the suite" and determined the hot water heater was the source of the gas, the suit alleges.

The lawsuit adds a number of reports from prior guests who also alleged they suffered symptoms consistent with carbon monoxide poisoning after staying at the resort. In response to those poor reviews, the Royal Kahal said it was "happy to announce that we have installed carbon monoxide detectors in all of our rooms as well as have detailed air quality tests done."

After the women died, an investigation revealed that the suite did not have a functional carbon monoxide detector, the suit says.

Following their deaths, the Royal Kahal replaced the faulty heaters with electric water heaters, according to the lawsuit.

The lawsuit alleges the Royal Kahal should have known about the dysfunctional heaters and the exposure to carbon monoxide and should have warned guests "of the dangerous condition" at the hotel.

The plaintiffs allege negligence, wrongful death, failure to warn and negligent misrepresentation against the Royal Kahal.

The lawsuit also lists breach of implied warrant of merchantability - including defective design and product, failure to warn and inadequate warnings and instructions - the undertakers doctrine and product liability against the company that makes and installs the water heaters that allegedly malfunctioned.

A jury trial has been requested, according to the lawsuit, to determine damages for wrongful death.