The families of three people who were killed during a helicopter crash, which collided with a 1,000-foot radio tower in Houston last month, have opened a lawsuit against the owners of the helicopter, the touring company that operated it, and the owners of the radio tower.

As reported by the Houston Chronicle last week, lawyers confirmed that a lawsuit is seeking $50 million in damages.

The helicopter crashed into a 1,000ft radio tower in Houston, Texas, on October 20, killing all four people on board, including the pilot.

It hit the structure at around 7:54pm, and was reportedly flying at around 600ft when it collided with the tower.

Reports at the time suggested that lighting on the tower failed days before it was hit by the helicopter.

The tower itself is owned by SBA Communications, which according to Wireless Estimator, only took ownership of the tower on October 10 after acquiring the tower from Univision, which had the structure since it was built in 1987.

The Houston Chronicle reported that the lawsuit was brought on behalf of the families of Cesar Lerma, Marie Alonso, and their nine-year-old son Dylon Lerma, who died in the crash along with helicopter pilot Samantha Grandbouche.

National Helicopter Solutions, Porter Equipment Holdings LLC, and SBA Communications have been named in the lawsuit, while Grandbouche has also been named as a defendant.

The lawsuit was filed a day after the National Transportation Safety Board released a preliminary report about the crash, which noted that the pilot, Grandbouche, was speaking with an air traffic controller shortly before the crash, and had received directions to avoid another helicopter flying around downtown Houston.

The report didn't specify any conclusions as to what caused the crash.

Its investigation also didn't confirm whether the lighting on the radio tower were flashing prior to the fatal crash.

“The families of Cesar, Marie, and Dylon are devastated and seek both answers and accountability,” said attorney Randy Sorrels. "We hope this lawsuit will answer many unanswered questions, bring about air-safety changes, and prevent a tragedy like this from ever happening again.”

Questions around the lighting of the tower were also asked in the release announcing the lawsuit, whether the pilot was properly trained, and if the helicopter was properly equipped to fly at night.

Last month, SBA spokesperson Lynne Hopkins said the company is cooperating with authorities on a full investigation. DCD has contacted SBA for further comment.

Meanwhile, National Helicopter Solutions' website appears to be down.

DCD's sympathies go out to the family and friends of those involved in the incident.