Texas floods: Fort Hood Death Toll Rises to 9

(CNN) Fort Hood officials have released the names of eight of nine soldiers who died in an accident when an Army truck in overturned in floodwaters at Fort Hood, Texas.

Staff Sgt. Miguel Angel Colonvazquez; Specialist Christine Faith Armstrong; Pvts. First Class Brandon Austin Banner and Zachery Nathaniel Fuller; Pvts. Isaac Lee Deleon, Eddy Raelaurin Gates and Tysheena Lynette James; and Cadet Mitchell Alexander Winey were all killed, the army said.

The one remaining soldier's name will be released once their next of kin has been informed.

The twelve were on a training mission when their vehicle became stuck in the flooded creek in a remote section of the post Thursday.

Soldiers in a following vehicle rescued three of their comrades after the Light Medium Tactical Vehicle (LMTV) overturned at Owl Creek on June 2, Maj. Gen. John Uberti told reporters.

Carter: Investigation promised

U.S. Defense Secretary Ash Carter, speaking at a press conference in Singapore, said the incident will be investigated. "As always, we'll get to the bottom of this incident and others that occurred this week."

Christopher Haug, spokesman for the post, said the troops were learning to operate the LMTV and were not sent out in conditions too dangerous for training.

"It was a situation where the rain had come and the water was rising quickly," he said. "They regularly pass through these weather conditions like this. This was a tactical vehicle, and at the time they were in proper place. Just an unfortunate accident that occurred quickly."

Owl Creek regularly experiences flash floods, said Michael Harmon, emergency management coordinator for Bell County.

'Routine' training mission

Haug declined to go into detail about the training mission except to describe it as "routine."

Retired Col. Robert Morgan, however, told CNN affiliate KXXV-TV that the LMTV may not operate well in high waters. The truck, which is used to transport troops and cargo, sits from 6 to 8 feet off the ground.

Severe storms have pummeled Texas, leading to a record rainfall total in May.

Gov. Greg Abbott has declared a state of disaster across 31 counties as more rain is expected.

CNN meteorologist Chad Myers warned that saturated ground and swollen creeks, bayous and rivers cannot absorb the downpour.

Evacuation orders expected

Abbott warned residents that evacuation orders may come soon because the Brazos River could easily continue to rise.

He said he was stunned at the amount of flooding, noting the people were using air boats on highways when flying over the area.

"I saw neighborhoods that were literally islands, completely surround by water," he said, noting that other Texans were ferrying food and water to the people trapped in houses.

He promised if residents left their homes that the Texas National Guard and police would protect their property. He warned drivers not to think they could ford flooded areas; he noted some people were driving around barricades and entering dangerous zones.

Mosquitoes also a threat

More showers and thunderstorms are predicted to hit parts of Texas, Oklahoma, and Louisiana over the weekend.

"Heavy rainfall will likely occur - maintaining a major risk for flash flooding through the weekend,"according to the National Weather Service's Prediction Center. Flood advisories have been issued for several counties in Texas, including the south and central parts of the state.

The National Weather Service also warned against driving in flooded roads, noting that "most flood deaths occur in vehicles."

Myers warned the aftermath would bring a different threat: mosquitoes.

Stagnant water will likely not recede for weeks, and the insects were already buzzing.

"This will last for weeks. I don't have to tell you what that means for West Nile, for Zika," Myers said, referring to two viruses spread to humans by mosquitoes.

Record rainfall

With 7.51 inches of rain in the first two days of June, Houston has surpassed its monthly average rainfall for the month -- 5.9 inches.

Fort Bend County, near Houston, is experiencing flooding it called "unprecedented," its Office of Emergency Management said.

Judge Bob Hebert said there have been more than 558 rescues and at least 1,400 homes affected by the water.

He noted the Brazos River was at nearly 55 feet under the Richmond Bridge -- 4 feet above the previous record set in 1994.

"That is a lot of water," he said.

He warned residents to be prepared for quickly rising waters and evacuate even if water had not yet entered their homes.

500-year floods

It's the second year in a row that Texas has been hit by 500-year floods -- an extreme event with odds of it happening only once every 500 years

Meteorologists and other experts point toward climate change or the weather pattern El Niño as potential culprits.

"It could just be really bad luck," said CNN senior meteorologist Brandon Miller.

"It just so happens that parts of Texas have seen them now in back-to-back years, and maybe even twice this year."

Climate change is a possible culprit because one of the expected effects from a warmer climate is heavier rainfall, prompting more flooding, such as that in South Carolina last year, Miller said.

But scientists have had mixed results in attributing the flooding to climate change, he said.

CNN's Tina Burnside, Dave Alsup , Amanda Jackson, Ed Lavandera, Jason Morris and Meron Moges-Gerbi contributed to this report.