Killeen, Tex. (NewsNation Now) — The Navajo Nation has joined calls for an accounting of the deaths at Fort Hood after one of its members became the latest soldier from the U.S. Army post to die this year.

Pvt. Corlton L. Chee, a 25-year-old soldier from Pinehill, New Mexico, died Wednesday after he collapsed following a physical fitness training exercise five days earlier, according to officials at the Central Texas post.

“There is something wrong at Fort Hood,” said U.S. Rep. Henry Cuellar (D-TX).

Cuellar told NewsNation affiliate KXAN that at least 15 soldiers stationed at the Central Texas Army base have disappeared or died since January. However, according to data obtained by The Associated Press, Chee was the 28th soldier from Fort Hood to die this year.

The Navajo Nation Council praised Chee in a statement Friday and urged the Army to thoroughly investigate his and the other soldiers’ deaths.

“We are deeply disturbed by the string of deaths at Fort Hood, and if there is any malfeasance or negligence involved, the Navajo Nation calls on our national leaders to pursue every available avenue to protect the lives of our Navajo warriors and those serving in the U.S. Armed Forces,” Speaker of the Council Seth Damon said.

Army officials have said Chee’s death is being investigated and that an autopsy would be performed by the Southwestern Institute of Forensic Sciences in Dallas. In a statement, they said he died at a hospital near Fort Hood in the company of his family.

Last week, the Army announced changes in the leadership at Fort Hood amid what they said was a widening investigation into the killing of another soldier at the post. A fellow soldier allegedly bludgeoning Spc. Vanessa Guillen to death has prompted calls for the military to change the way it handles sexual abuse and harassment.