The family of Riley Strain, a University of Missouri student who was found dead after he disappeared while drinking with his fraternity brothers in Nashville, Tennessee, last year, filed a wrongful death lawsuit against the organization and some of its members.

The lawsuit, filed in Boone County, Missouri, on Friday and reviewed by HuffPost, named the Delta Chi fraternity and 32 of its members, accusing them of negligence by failing to have adequate safety precautions to protect Strain and ensure that the fraternity brothers did not drink too much the night he went missing.

The family described Strain as “an often-reserved young man that did not tend to go with the typical fraternity flow.” They said he did not initially plan on attending the Delta Chi spring formal in Nashville but gave in after other members of the fraternity pressured him, according to the lawsuit.

Strain boarded a charter bus with his fraternity brothers headed on March 8 last year and was offered several alcoholic beverages while traveling, according to the lawsuit.

“Although it was supposed to be prohibited, this type of conduct was typical for the Delta Chi formal. It would have disastrous results for Riley,” the lawsuit reads.

Within hours of arriving in Nashville, several of Strain’s fraternity brothers noticed he was acting strange and having “difficulty speaking, walking, and interacting with those around him,” according to the lawsuit. Despite this, Strain and his brothers continued to party, but by the time they reached the final bar of the night, Strain “was virtually incoherent.”

The lawsuit claims Strain’s fraternity brothers had two choices after being kicked out the final bar they had visited that night ― they could “go with Riley, make sure he was safe, and take care of him” or “continue to party.” Strain’s fraternity brothers continued partying, and by 9:53 p.m, Strain disappeared without them noticing.

“Without help, [Strain] immediately began walking in the wrong direction and away from the hotel where the fraternity was staying and towards the Cumberland River,” the lawsuit read. “He began stumbling and falling while walking on flat surfaces. Rather than having the support of his brothers, Riley was abandoned and alone.”

Strain’s body was found facedown in the river on March 22. Medical examiners determined Strain’s cause of death was from accidental drowning and intoxication. His blood-alcohol level was 0.228, nearly three times the legal limit for driving, and he had delta-9, a THC compound, in his system.

The fraternity’s national headquarters did not immediately respond to a request for comment from HuffPost.