The system of devastating twisters that cut through the nation's midsection, leaving 44 people dead from Kansas to Georgia, marked the most active week of tornadoes (search) on record, meteorologists said Saturday.

The deadly tornadoes began early in the week in Missouri, Kansas and Tennessee, followed by two rounds of twisters in the Oklahoma City (search) area Thursday and Friday. Storms combined with straight-line wind, lightning and floods as they reduced hundreds of homes and businesses to splinters and piles of loose bricks.

"We just don't have a down day; that's what's been very unusual," said Rich Thompson, lead forecaster at the Storm Prediction Center of the National Weather Service (search), in Norman, Okla. "It just doesn't seem to stop."

Storms pelted several states on Saturday, although they weren't as severe as some of the earlier turbulent weather.

A system in Missouri spawned tornadoes that damaged outbuildings, overturned cars and downed power lines. The worst damage appeared to be in the town of Canton, about 150 miles northwest of St. Louis, where officials said early reports indicated 20 to 30 houses and 10 mobile homes were damaged. No deaths were reported.

Mayor Terry Fretwell told KMOV-TV in St. Louis that the field house at Culver-Stockton College and a grocery store were destroyed and a motel suffered major damage.

Four people were taken to Blessing Hospital in Quincy, Ill., and were being evaluated in the emergency room, a hospital administrator said.

At least one tornado touched down in Indiana. Torrential downpours flooded streets and fields and forced the postponement Saturday's qualification for the Indianapolis 500.

In Kentucky, 10 people were injured after a storm swept through the northeastern part of the state. The National Weather Service confirmed a tornado in the area.

Tornadoes were also spotted Saturday in six central Illinois counties, damaging homes and pelting trees, officials said. At least one death was reported.

Officials said tornadoes from the same system destroyed homes and damaged barns in southeast Iowa while penny- to grapefruit-sized hail pounded parts of the state. No injuries were reported.

More than 100 people were injured in the Oklahoma City area by two tornadoes that struck Thursday and Friday night. But only a few were hospitalized Saturday, and only one remained in critical condition.

President Bush issued a disaster declaration Saturday for Oklahoma, clearing the way for federal aid. Earlier in the week, he did the same for tornado-battered parts of Tennessee, Kansas and Missouri.

More than 300 homes and 35 businesses were destroyed in Oklahoma alone and the state insurance commissioner's office gave a preliminary damage estimate of $100 million. Utility crews strung new power lines in an effort to restore electrical service to more than 10,000 homes and businesses. About 8,300 homes were without power Saturday evening.

While tornadoes are common in May, the number of them reported in the first part of this month has been extraordinary, said Dan McCarthy, warning coordination meteorologist at the Storm Prediction Center.

By Saturday, about 300 tornadoes had been reported since the start of May, about 100 more than the most recent comparable rash, in 1999. Until now, that 1999 barrage had been the record for any 10-day period since record-keeping started in the 1950s, said Dan McCarthy, warning coordination meteorologist at the Storm Prediction Center.

About 70 percent of all tornadoes are reported in April, May and June.

"What is happening this week is that we have a persistent warm air mass in place and a persistent jet stream extending from the Southwestern United States into the central Plains," McCarthy said.

Those conditions were ripe for producing thunderstorms, which can rotate and form tornadoes.

Changing weather conditions were expected to reduce the risk beginning Sunday.

Because of the tornadoes and other emergencies this year, the American Red Cross said Friday its disaster relief fund, which typically has a $50 million cushion, had dwindled to just $5 million. Executive vice president Terry J. Sicilia estimated that the costs of the recent tornadoes could deplete the fund entirely if more donations don't come in soon.

The twister that struck the Oklahoma City area late Friday approached the metropolitan area from the southwest, then skipped through the city, snapping utility poles, flipping a light airplane parked at Wiley Post Airport and ripping apart an elementary school.

Damage was spotty. A mower repair shop near the airport was totaled, but nearby homes had only minor damage.

"From what we've seen there was significant damage, but it was not continuous, not widespread for a tornado moving through a major metropolitan area after dark on a Friday night," said Rick Smith, a weather service meteorologist.

Thursday's tornado blasted a 19-mile-long path through Oklahoma City's southern suburbs, injuring more than 130, destroying more than 300 houses and businesses and damaging hundreds more. Unlike Friday's twister, that tornado stayed on the ground for most of its route.

The Associated Press contributed to this report.