CHATTANOOGA, Tenn. (AP) — A mother, father and child were killed when a tree fell on their car during heavy rain and flooding in Tennessee, where submerged roads also led to dramatic rescues of people trapped in their cars, authorities said Wednesday.

The three were killed when saturated ground caused a large tree to fall in the Chattanooga suburb of East Ridge just after midnight, Hamilton County Office of Emergency Management spokesperson Amy Maxwell said.

Additionally, a body was found when authorities were searching for a man who was swept away when he ran past firefighters and a barricade that blocked a flooded road Tuesday, according to the Chattanooga Fire Department. The local police and medical examiner will determine the cause of death.

The flooding prompted rescues of people stuck in homes and swamped vehicles. Hamilton County Mayor Weston Wamp declared a local state of emergency Tuesday night. Residents were urged to exercise extreme caution.

At a news conference Wednesday, officials said they didn’t expect so much rain and flooding to hit so quickly.

At one point, there were 60 vehicles on the flooded interstate, said Chris Adams, director of emergency management for Hamilton County. Some first responders were carrying people on their backs who couldn’t move well through the water, and dropped them off on the raised divider in the middle of the highway, Adams added.

“We all know to ‘turn around, not drown,’ but when you look at it and it’s 2 inches deep, and then next thing you know it’s 4 feet deep, that’s something you’ve never seen before,” Adams said.

There were so many calls for help that 911 calls were “holding in every minute of every hour for about three hours straight,” with a more than 940 calls between 6 p.m. and midnight, said Barbara Loveless, director of operations for Hamilton County 911.

Troy Plemons, a communications systems technician for EPB, Chattanooga’s electricity and telecommunications utility, said he was stuck in traffic on an interstate in his bucket truck for two to three hours on Tuesday evening when the area started to flood quickly.

Then Plemons said he saw the water pick up an SUV, and when he and two Lawson Electric workers encouraged a woman inside to get out, she threw up her hands like she didn’t know if she could. Plemons moved to the bed of a truck next to him to try to get closer to the woman, but the water was getting up to her chest and he said he realized someone was going to have to go in to get her.

“I didn’t think there was any time,” he said. “I tried my best.”

Plemons said the water was reaching neck level for the woman in the SUV when he used a boring bit offered by the Lawson Electric workers to break the window and helped the woman get out.

“It was a rush for sure. I felt like I was pretty calm until I broke the window,” Plemons said. “I was doing everything I could to get her out because the water was rising pretty quick.”

He helped the woman to the road and she sat down in his vehicle to warm up for a while. There were several rescues of people whose cars were overwhelmed by water in the area until the water receded about two to three hours later and traffic began to move again, Plemons said.

“I felt like I was there at the right time,” he said. “I’m thankful I was there to help that lady.”

The National Weather Service issued a flood watch for much of middle Tennessee through Wednesday night, warning of scattered flash flooding with tropical-like heavy rainfall and the possibility of training storms, especially over already saturated areas.

The airport in Chattanooga recorded more than 6.4 inches (about 16 centimeters) of rain Tuesday, marking the second-wettest day recorded for the city dating back to 1879, according to a social media post by the National Weather Service in Morristown. The highest single-day total was nearly 9.5 inches (24 centimeters) in September 2011 from the remnants of Tropical Storm Lee, the weather service said.

Chattanooga Fire crews rescued people trapped in vehicles and residents stuck in their homes, fire department officials said. Flooding closed parts of Interstate 24 in the area, but it reopened once floodwaters receded.

Swiftwater rescue teams rescued residents of three East Ridge homes trapped by rising floodwaters, according to the Hamilton County Sheriff’s Office.

Wamp, the mayor, said he toured East Ridge on Wednesday. He said that though there was a tragic loss of life, the property and infrastructure damage was “not as bad as I thought it would have been based on the way things looked last night.”