Updated

One Mississippi National Guard member was killed and three others were injured when their tank rolled over during a training exercise in the California desert.

Investigators were trying to determine what caused the death and injuries Monday night at the National Training Center at Fort Irwin, a remote facility 37 miles (60 kilometers) northeast of Barstow in the High Mojave Desert midway between San Bernardino and Las Vegas.

A military helicopter flew the three injured soldiers to a hospital in Loma Linda. Two have been released, and one was in stable condition Tuesday. The names of all four are being withheld until 24 hours after their families are notified.

The members of the 155th Armored Brigade Combat Team, based in Tupelo, Mississippi, were participating in a two-week-long training exercise, which focused this week on maneuvering tanks, said Kenneth Drylie, spokesman for the center. Drylie said this week's scheduled exercises did not involve live-fire training.

The troops were doing an armored brigade combat team exercise, which emulates an overseas deployment to a war zone, Drylie said. Also participating in the training are National Guard members from California, Missouri, and members of the Air Force.

Later in the training, troops will participate in a mock battle with 5,000 troops squaring off against 5,000 others designated as enemy forces, Drylie said.

He declined to comment further, saying the accident is under investigation.

Lt. Col. Christian Patterson, spokesman of the Mississippi National Guard, said the exercise has been suspended for the unit that the four members belonged to, but the rest of the Mississippi Guard troops will still participate. He said no further details would be released to avoid compromising the investigation.

The center is one of the few places in the country with room for 10,000 troops to battle each other. It does 10 such training exercises a year with all branches of the military using the facility, Drylie said.

"It's basically like a full deployment overseas except that it's in the California desert," Drylie said.