(CNN) -- The remnants of Tropical Storm Erin turned central Oklahoma into a wash basin Sunday, with rescuers on helicopters plucking people from flood waters and rooftops and ferrying them to safety.
A flood victim hangs precariously during a rescue flight Sunday.
Two people died and at least two others were hurt, said Michelann Ooten, a spokesman for the state's emergency operations center in Oklahoma City.
A middle-aged man who had stopped to help another person wound up drowning in his vehicle near Kingfisher, Oklahoma, and an elderly woman in Fort Cobb, Oklahoma, who had sought protection in her storm cellar drowned there, Ooten said.
The injuries occurred when either straight-line winds or a tornado destroyed a house in Watonga, she said.
"I'm certain there are many more injured," she said. "This is all courtesy Erin, the new four-letter word," she said.
Officials were searching for three other people who had been traveling together near Carnegie, Oklahoma, and were reported missing, she said.
In Kingfisher, Oklahoma, the storm dropped five to 11 inches of rain in a short period of time, causing Kingfisher Creek to rise 25 feet and overflow its banks, said Capt. Chris West of the Oklahoma Highway Patrol.
"It's the highest it's ever been," West said. "There's about 200 to 300 people that are displaced out of their homes."
By 6 p.m. floodwaters in Kingfisher had begun to subside, but the storm system had not yet exited the state, Ooten said. Flood warnings were issued until midnight for parts of eastern Oklahoma, she said.
The helicopter rescue operation got under way Sunday morning, after authorities got a call alerting them that a pickup truck containing two passengers had been swept from a bridge over Kingfisher Creek, West said.
First, a helicopter dropped life vests to the couple, whose pickup truck was nearly obscured by the water. Soon afterward, their truck was simply swept away, and the pair were left to fend for themselves in the water until the rescue helicopter approached.
First, a rescuer grabbed the woman and pulled her toward the skid on which he was positioned. For a few seconds, she held on as the helicopter rose, but lost her grip and fell back into the water.
The helicopter circled back for a second effort, which this time proved successful.
The drama from the town of about 14,000 residents 35 miles northwest of Oklahoma City unfolded live on national television.
"When the lady fell, I was kind of surprised, I hated to see that," said West, who watched the rescue on television. "We were able to get back around, get her picked up."
Like his partner, the man also fell, was picked up again and taken to safety.
The rescue work then focused on removing people stranded atop the roofs of vehicles and buildings. Time and again, the pilots positioned their helicopters inches above choppy water as rescuers helped men and women grab the skids.
Residents of nearby Apache, Oklahoma, faced similar floods, which caught most people off guard, said Lt. Bobby Claborne of the Apache Fire Department.
"We never thought we'd have a tropical storm in our area," he said.
No evacuation plans were initiated until early Sunday, "but it was a little late" by then, he said.
For several hours, thousands of people were without power in El Reno, which had been inundated by more than six inches of rain in just a few hours. And some vehicles were trapped on Interstate 40 in western Oklahoma, said Capt. Ken Brown, the state police operations commander in El Reno.
"Two different semis were overcome by water and required fire rescue to get the drivers from their vehicles," he said.
Boats and other watercraft were enlisted in the rescue effort.
West said the flooded areas have sustained extensive damage -- "not only to homes and businesses and automobiles, but to these agricultural areas."
"We have a lot of roadways that will be damaged from this," he said. "There's going to be a lot of debris that floated in. And you know, road crews are going to have to get out and clear those."
Meanwhile, floods around the upper Midwest washed away roads and bridges, killing four people,The Associated Press reported. Floods killed two in Minnesota when their car drove off the road and they could not escape their vehicle.
In Vernon County, Wisconsin, a mudslide was triggered by a foot of rain, the AP said. E-mail to a friend
All About Oklahoma