The parents of two Lakeville South High School students killed in a car crash in 2015 while playing "Nerf wars" have sued the school district for failing to protect the teens from a known danger.

Jacob Flynn, 17, and John Price IV, 18, were killed Dec. 4, 2015, after the driver of the truck they were in veered and overcorrected, causing the vehicle to roll multiple times. The two teens were ejected in the crash. The driver and another passenger survived. Law enforcement determined that a Nerf war was a factor in the crash.

Greg Walsh, the lawyer for the families, said the issue isn't Nerf wars itself but the school's failure to protect the students from danger. "They knew that kids were getting hurt. They knew this was escalating," he said. "They had an opportunity to protect the kids from a known danger and they failed."

Nerf wars, a long-running game played by high school students, is often banned from school grounds. In the game, students can be "kidnapped" and taken to other locations and shot with a spongy Nerf projectile. The aim is to score points and win a pot of money.

As evidence that the schools were aware of the game, the lawsuit pointed to two Twitter handles @SouthsideNerf and @NorthNerf that students used and that were followed by teachers, the district, football coaches and others.

According to the rules, schools and places of worship were safe zones, meaning nobody could be "killed" there, but students would "kidnap" others and take them elsewhere for "assassination."

The lawsuit said students were often forcibly kidnapped from the school parking lot immediately after school was dismissed. "It was commonplace that students would be chased throughout the ... parking lot, running in and out of cars, as students were leaving for the day," the lawsuit said.

The lawsuit also cited a warning e-mail sent by activities director Neil Strader to administrators two months before the crash. Strader said he had concerns about the Nerf wars and wanted to make sure others were aware of what was happening. "A boy [was] punched Wednesday during Nerf War and a police report [was] made," he wrote.

Walsh said a lawsuit over Nerf wars may be unique but that school districts have been held liable in similar situations for injuries suffered by students involved in off-campus activities that were known to administrators.

No charges were filed in the crash. At the time, Dakota County Attorney James Backstrom said the four teens were willing participants in the game, and Flynn got into the truck knowing the three others were on an opposing team.

Backstrom also said, "These types of games, which can involve aggressive behaviors among youth, have no place in our schools and communities and should end."

About 30 seconds before the crash, Price jumped from the back seat to the front, according to the investigation. Flynn, who was still in the back seat, may have leaned forward to avoid being shot with the Nerf gun or may have tried to gain possession of it, according to the other teen in the back seat, who was wearing a seat belt and suffered minor injuries.

The lawsuit was filed against Independent School District 194. In a statement, the district said Thursday, "We continue to grieve for the loss of Jacob Flynn and John Price. However, the auto accident that claimed Jacob and John was in no way connected to a sanctioned or supported school activity, in fact the single car accident was over two miles away from the school after school was over for the week. Therefore there is no liability or fault on behalf of Lakeville Schools."