Mia Le walks down Aqua Vista Drive past flooded townhouses as she tries to make her way home Thursday, June 2, 2016 near Kingwood, Texas. Parts of Texas have been inundated with rain in the last week, and more than half of the state is under flood watches or warnings, including the counties near Fort Hood. At least six people died in floods last week in Central and Southeast Texas. (Michael Ciaglo/Houston Chronicle via AP) MANDATORY CREDIT
Mia Le walks down Aqua Vista Drive past flooded townhouses as she tries to make her way home Thursday, June 2, 2016 near Kingwood, Texas. Parts of Texas have been inundated with rain in the last week, and more than half of the state is under flood watches or warnings, including the counties near Fort Hood. At least six people died in floods last week in Central and Southeast Texas. (Michael Ciaglo/Houston Chronicle via AP) MANDATORY CREDIT Credit: Michael Ciaglo

Fort Hood, Texas — Fort Hood commanders were in the process of closing roads on the sprawling Army post in Central Texas when a truck carrying 12 soldiers overturned in a fast-flowing flooded creek during a training exercise, killing nine and injuring three, officials said Friday.

The portion of road on the northern fringe of the post where the Light Medium Tactical Vehicle overturned Thursday hadn’t been overrun by water during past floods, Fort Hood spokesman Chris Haug said. The vehicle resembles a flatbed truck with a walled bed and is used to carry troops.

He said during a news conference Friday that the soldiers were being trained on how to operate the 2½-ton truck when it overturned along Owl Creek, about 70 miles north of Austin.

“It was a situation where the rain had come, the water was rising quickly and we were in the process, at the moment of the event, of closing the roads,” Haug said.

Soldiers on training exercises regularly contend with high-water situations following heavy rains, he said.

“This was a tactical vehicle and at the time they were in a proper place for what they were training,” Haug said. “It’s just an unfortunate accident that occurred quickly.”

Three soldiers were found dead shortly after the vehicle overturned. The bodies of two others were found late Thursday night. Four others were discovered dead Friday.

The three injured were released from Fort Hood’s hospital on Friday.

The Army has not yet released the names of the dead because it was still notifying relatives.

“This tragedy extends well beyond Fort Hood and the outpouring of support from the country is sincerely appreciated,” Maj. Gen. John Uberti said.

Crews used helicopters, boats and heavy trucks to search the 20-mile creek, which winds through heavily wooded terrain. At Owl Creek Park, where the creek feeds into Lake Belton at the northeast edge of Fort Hood, the creek is normally 30 to 40 feet wide was swollen Friday to some 500 feet wide.

The 340-square-mile post, one of the nation’s largest, has seen fatal training accidents before. In November 2015, four soldiers were killed when a Black Hawk helicopter crashed during a training exercise. And in June 2007, a soldier who went missing for four days after a solo navigation exercise died from hyperthermia and dehydration while training in 90-degree heat.

This week’s Texas storms are the latest in a string of torrential rains since May 2015 that have put swaths of the state under water. Nearly the entire eastern half of Texas, including Fort Hood, was under flash flood warnings or watches Friday.

Storms moving in from the Gulf of Mexico threatened to worsen flooding in places like Brazoria and Fort Bend counties, southwest of Houston, where residents near the Brazos River were forced from their homes.