(Editor's note: This article has been updated throughout and to correct the date of the press conference.)

DALLAS — The families of three victims who died in the September 2014 collision between a semi-truck that crossed a highway median and struck a bus carrying North Central Texas College softball players hosted a press conference with their attorney in Dallas Wednesday, announcing that their lawsuit against the bus manufacturer is intended to end the company’s use of allegedly unsafe vehicle-building materials.

The press conference, hosted by attorney Todd Tracy, comes just days after Russell Staley’s suicide. Mr. Staley was the driver of the semi-truck and was set to stand trial in early March for his role in the collision. The destroyed bus itself served as the backdrop for the press conference and the victim’s parents.

Tracy said the civil lawsuit against Champion Bus Inc. will go to trial on May 8 in the 325th Judicial Court in Gainsville and the case is centered on the “crash-worthiness” of the 2008 model year Champion Defender Bus, which NCTC used to transport its softball players.

“You just don’t build a vehicle like this,” Tracy said. “It doesn’t matter if it’s a bus like this or a passenger vehicle or an SUV. You want to provide proper restraints, you want to prevent an ejection, you want to prevent collapse, you want to prevent fires and distribute and channel energy.”

Tracy said Champion Bus used unsafe materials including what he described as thin plywood, weak metal framing, unsealed windows and outdated safety belts. He said the materials directly contributed to the deaths of four of the young women on the team and the injury of 11 others. The destroyed bus sat parked behind the victims’ parents, who saw the vehicle in-person for the first time Wednesday. They wiped away tears and comforted one another as they spoke of their inspection of the bus and the loss of their daughters.

The fatal collision occurred on Sept. 26, 2014 as the NCTC softball team was traveling south on Interstate 35 in Oklahoma, returning to Gainesville from a scrimmage earlier in the day. Mr. Staley is alleged to have drifted across the grass median as he traveled north on the freeway in his Quickway Transportation semi and struck the team’s bus.

A report compiled by the National Transportation Safety Board concluded that Mr. Staley’s vehicle drifted into oncoming lanes and struck the rear driver’s side of the bus, before rolling to a stop in a wooded area adjacent to the freeway. The bus, carrying 15 softball players, and other team staff rolled onto its side and came to a rest several hundred feet beyond the point of impact.

Killed in the crash were Brooke Deckard, 20, of Blue Ridge; Jaiden Pellton, 19, of Telephone; Megan Richardson, 19, of Wylie and Katelynn Woodlee, 18, of Dodd City. Three of the four fatally-injured were ejected from the bus. Five other team members were seriously injured and an additional six sustained minor injuries. Mr. Staley received minor injuries as well and was hospitalized following the crash.

Tracy said that the deaths and injuries that resulted from the collision would not have happened had the bus been better constructed with more crash-resistant and crash-absorbent materials. Despite the NTSB’s estimate that Mr. Staley’s semi was traveling at 76 miles per hour when it struck the bus, Tracy described the crash as relatively “low energy” and said stronger materials would have minimized the severity of the impact and the risk for injury.

“There should have been no one seriously hurt,” Tracy said.

Mr. Staley told investigators that he was reaching for a soft drink kept inside a cooler when he began to drift across the median and into the bus’ path, but the NTSB report said Mr. Staley’s claim did not match the crash evidence. A search of the cabin of Mr. Staley’s semi yielded a glass pipe, which was analyzed and found to contain synthetic marijuana. The substance also known as “K2” and “spice” is legally sold under the pretense that it is not for human consumption, but it is regularly smoked by users and has been known to cause disorientation, agitation and paranoia. The results of Mr. Staley’s post-crash drug test were inconclusive, but the NTSB report included information that Mr. Staley’s wife, a mental health counselor, and a workplace supervisor all voiced concerns about the affects of Mr. Staley’s use of drugs both at home and on the job.

The NTSB said Mr. Staley’s lack of corrective steering and braking contradicted his claim and the drugs were a likely factor in the crash.

“The lack of any type of evasive steering or braking by the truck driver while traveling across the median for more than 10 seconds — and the full throttle following impact with the medium-size bus — are inconsistent with a fatigue-related crash,” the November 2015 NTSB report says. “The truck driver’s lack of corrective actions following the roadway departure was due to incapacitation, likely from use of synthetic cannabinoids.”

Mr. Staley, 55, was found dead at his home in Saginaw on Jan. 27. The Tarrant County Medical Examiner said he died from a gunshot wound to the head and ruled his death a suicide. Mr. Staley was charged with four counts of first-degree manslaughter and was set to go on trial beginning March 8 in Murray County, Oklahoma.

Tracy said the parents of the three victims who attended the press conference felt empathy for Mr. Staley’s family. But Tracy said Champion Bus has not taken any of the NTSB-suggested steps to improve the safety of its buses.

“They haven’t done anything since the NTSB report,” Tracy said. "They refuse to accept any of the NTSB’s recommendations and put them on their newer buses.”

When asked whether Champion Bus was legally required to use stronger materials in the construction of its vehicles following the crash, Tracy said no. He did however state that the builder had an obligation to improve safety features.

“How about a moral requirement?” Tracy asked. “The vast majority of safety standards in the country today that the vehicle industry sets, they aren’t required to do it. They just do it because they understand that people get in their vehicles and lives are at stake.”

And that’s what Tracy and the parents involved in the lawsuit say they are concerned about. They contend that the deaths of their children could have been prevented and hope the lawsuit compels the bus company to improve safety features on it’s buses.

"It’s absolutely horrific to lose a child. I wouldn’t wish it on anyone.,” John Woodlee said, “I just hope these changes are made so it doesn’t happen again.”