HOUSTON — The families of five Houston firefighters – four who died and one who was injured in the 2013 Southwest Inn fire -- have filed a federal lawsuit against Motorola, claiming the company’s defective radios contributed to the firefighters’ deaths.

Anne Sullivan, Robert Garner, Matthew Renaud and Robert Bebee died in the May 13, 2013, blaze at the motel. Capt. William “Iron Bill” Dowling was among those injured in the fire and died last March from his injuries.

Related: Remembering the firefighters killed in the Southwest Inn fire

The lawsuit claims because of more than 18 minutes of radio delays caused by “malfunctioning and mis-programmed Motorola digital radios,” the victims could not be found in time.

The families hired forensic pathologist Michael Baden to review evidence in this case. Baden released a report saying the four firefighters killed in the blaze did not die from smoke inhalation, rather, they died because their oxygen ran out.

"That's what we're struggling with now is that they could have been rescued," said Mary Sullivan, Anne Sullivan's mother.

Attorney Benjamin Hall, who represents the families in the lawsuit, said a report from two independent radio experts found Motorola’s digital radios were mis-programmed and malfunctioning on the day of the fire, causing a delay for responders to be able to reach the firefighters by up to 18 minutes. One first responder testified had he had just 3 minutes of that delay, he would have been able to rescue two of the firefighters.

"When we went around and looked over Motorola's track record in other cities, these are repeated complaints that these radios are failing," Hall said. "Hopefully, Motorola will do a better job with its radios before putting them out in the field."

Motorola released the following statement:

"The events of May 31, 2013 were horrifying and tragic and our hearts go out to the victims and their families. However, Motorola Solutions strongly disagrees with the summary provided by the plaintiffs’ attorney.”