Nine soldiers have died after their vehicle was caught in flood waters near a US army barracks at Fort Hood in Texas.
The area has been hit by particularly heavy rains and the soldiers' truck overturned in a rain-swollen creek.
A unit of a dozen soldiers were in the truck at the time, reportedly learning to drive the vehicle.
Search and rescue teams consisting of aircraft, boats and dogs recovered four bodies on Friday.
Five bodies had been found a day earlier, according to the army.
Three soldiers survived the incident, which occurred on Thursday, and they have since been discharged from hospital.
Fort Hood spokesman Chris Haug said the manouvers at Owl Creek had been routine, but that a full investigation was now under way.
The road on which the unit had been driving was "designated a low-water crossing", he said, meaning it would not have been considered prone to flooding.
Southeast Texas has been hit by severe flooding in recent days, forcing more than 1,000 people from their homes and leading to a number of deaths across the state.