A soldier preparing for a training activity died Friday evening at Fort Jackson, South Carolina, post officials announced on Saturday.

The 18-year-old was about to do physical training at his battalion area when he showed signs of distress and suffered a “medical emergency,” officials said.

The soldier’s name had not been released as of Saturday afternoon, pending notification of the soldier’s family.

The cause of death is under investigation.

Medical responders at Fort Jackson took him to a local hospital, where he was pronounced dead at 8:30 p.m. Friday, according to a release from Fort Jackson.

Hospital staff ruled out heat problems as a potential cause of death.

“Separate investigations will be taking place to determine the facts behind the incident and provided in time to our Soldier’s family, who rightly deserve this information,” Brig. Gen. Milford H. Beagle, commander of the U.S. Army Training Center and Fort Jackson, said in a message on the post’s Facebook page and Twitter.

“Our deepest condolences & support to the 3rd Battalion, 60th Infantry Regiment “RIVER RAIDERS” on the loss of a Soldier in Training,” Fort Jackson officials said on Facebook.

“We are deeply saddened by the loss of one of our own. Our hearts and prayers are with the family members and teammates of the deceased soldier. We are providing every comfort and assistance we can to all involved,” Beagle said in his message.

“The tragic loss of a Soldier, our nation’s most precious resource, is devastating to the families, friends and teammates,” he said.