A search for two children missing since they were swept away in floodwaters in North Carolina continued Wednesday morning.

A 5-year old girl and her 4-year old brother went missing after the car their mother was driving was carried away in a flash flood in Smithfield, North Carolina, about 30 miles south of Raleigh.

Smithfield Fire Chief John Blanton said at a Tuesday news conference that the children’s mother, who has not been named, called 911 around 11:30 p.m. Monday, saying her car had been overtaken by water from a flooded creek.

Smithfield rescue crews, along with emergency service workers from neighboring towns, responded with four boats to the scene, Blanton said.

Initially, rescue crews were able to locate the car and retrieve the mother and one of her children on one of the responding boats.

But, the fire chief said, “The water was so turbulent the boat capsized, and they lost the child,” Blanton said.

All four boats capsized at some point in the rescue efforts, Blanton said.

“The amount of water, and the current is so strong, it overcomes you when you start to turn a boat, and you’re in debris and tress and such,” Blanton said, according to NBC Raleigh affiliate WRAL. “They would hit a tree, they’d flip over.”

The mother and two first responders were taken to the hospital early Tuesday for injuries, WRAL reported.

Search crews were able to locate the car again on Tuesday, but were not able to find the two missing children.

Up to about eight inches of rain fell on Smithfield during a storm Monday. The creek that flooded was about a half mile long, Blanton said.