Kirksville, Mo. -- The parents of two students who killed themselves at a Truman State University fraternity house are suing the Missouri school, the fraternity and a fraternity member who they claim encouraged the suicides. The joint lawsuit filed in Adair County also links the fraternity member to two other suicides in the same academic year and a fifth death that remains under investigation, The Kansas City Star reported.

The parents of Alexander David Mullins, of Kansas City, and Joshua Michael Thomas, of St. Louis, allege in their lawsuit that the school and others knew their sons struggled with depression and didn't act to protect them before they killed themselves at the Alpha Kappa Lambda House. Mullins lived at the house and Thomas lived in campus housing.

The Alpha Kappa Lambda house at Truman State University. KTVO

Their attorney, Nicole Gorovsky, alleges in the lawsuit that a fraternity member gave his friends "advice on how to commit suicide." The Associated Press is not naming the fraternity member because he has not been charged with a crime.

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The lawsuit also links the fraternity member to two other young men who killed themselves but are referred to with pseudonyms. One also was a member of Alpha Kappa Lambda and the other socialized with them but wasn't a Truman State student. The suit also mentions the death of a woman, which remains under investigation. All five died during the 2016-17 academic year.

The five were friends of the fraternity member, who is no longer a Truman State student and lives in Illinois, said Gorovsky, who added that the student wasn't kicked out of the school, which is located in Kirksville, about 165 miles northwest of St. Louis.

A police investigation found that the fraternity member was the last person to see or talk to each of the other students before their deaths and had access to all of them, including keys to their rooms and apartments, Gorovsky said. The fraternity member told police that "he counseled people and gave advice and step-by-step directions to people on how to 'deal with depression and do their own free will,'" she alleges, saying the counseling included "advice on how to commit suicide."

"This tragedy was preventable," Gorovsky said. "This situation had been swept under the rug."

Kirksville police did not immediately return a phone call Thursday from The Associated Press seeking information on the status of the investigation.

After Thomas' death in April, CBS affiliate KMOV reported that Alpha Kappa Lambda issued a statement saying it was "devastated to lose Joshua Thomas." The fraternity added that it "offered our full cooperation to the university and local authorities."

Warren Wills, the school's general counsel, said Wednesday that the university provided counseling for fraternity members after the deaths and that a group was formed to provide ongoing support "to help them get their house in order."

"Young people who are college age are very susceptible to this type of difficulties," he said. He acknowledged that so many deaths within months involving the same fraternity "is certainly an unusual situation."

Wills said because the fraternity house is not on campus and is owned by Alpha Kappa Lambda, the university's only jurisdiction is to decide whether it remains a recognized student organization, and it remains an active fraternity at Truman State.

The parents are seeking monetary compensation. Gorovsky said if a settlement is reached, the parents would want the university's faculty and staff to be trained to recognize dangerous behavior "so no other students are hurt."

KTVO reports that Truman State University released the following statement in response to the lawsuit:

"We are aware that an attorney has announced the filing of litigation against the University pertaining to the deaths of two of our students. We strongly disagree with the allegations as stated in the lawsuit and will defend the suit vigorously. As the litigation proceeds, it will become clear that the University is not responsible for the deaths of these students. We will not comment further on this pending litigation."