Rescuers dug their way through the remains of houses and businesses on Wednesday after a rare and deadly February tornado ripped through a small Oklahoma town on Tuesday night. Nine people were dead, and 46 were injured, local authorities said.

Three people were rescued Wednesday after being trapped inside a house overnight, although as many as 40 residents were still unaccounted for in Lone Grove, in the south-central part of Oklahoma.

“I went through that Murrah Building bombing, and it reminds me of that,” said Sheriff Ken Grace of Carter County, referring to the 1995 bombing of the Alfred P. Murrah Federal Building in Oklahoma City, which killed 168 people.

By midafternoon on Wednesday, Sheriff Grace said crews had discovered a body in Lone Grove, a man who was found dead in his pickup in the middle of a field. “The tornado must have picked him up and dropped him there,” the sheriff said. The National Weather Service said the intensity of the tornado that struck Lone Grove was the second highest, EF4, on its scale, with winds equivalent to 170 miles per hour.

Marianne Elfert, the Lone Grove city manager, said the damage was extensive, especially in the southern section of her town of 5,000, about 100 miles south of Oklahoma City.

“We’re talking about normal structures destroyed, mobile homes, downed trees, downed power lines and utilities,” Ms. Elfert said. “We’re not sure what level of assistance we will receive.”

Gov. Brad Henry, who surveyed the damage in Lone Grove on Wednesday, declared a state of emergency in 17 counties.

Random mountains of mangled metal, overturned cars, strewn furniture and caved-in buildings confronted stunned local officials and residents, as the Oklahoma Highway Patrol and the National Guard assisted in the recovery. Officials from the National Weather Service also surveyed the damage to determine the intensity of the tornado, which struck the area about 7:15 p.m. Central time on Tuesday.

Two other tornadoes associated with the storm touched down in Oklahoma — in Pawnee and Edmond, a northeast suburb of Oklahoma City. There was property damage and loss of power, the authorities said, but there were no fatalities.