May 21, 2013 at 2:24 PM ET
The worst of it lasted for about an hour. But the human, physical and economic toll of the Oklahoma tornado will rank among the most devastating weather events of its kind.
"This is going to be one of the top five costliest tornadoes in U.S. history," said Evan Gold, senior vice president of client services at Planalytics, a weather consulting firm.
The full impact of the human loss was still unknown Tuesday as exhausted rescue workers searched for survivors among the piles of rubble and collapsed structures left behind in the mile-wide path of the killer storm in Moore, Okla. The effort was hampered by piles of debris, damage to roadways and heavy traffic.
Local officials said 24 were confirmed dead, including eight children. Hospitals reported that dozens more were being treated for injuries, at least 65 of them children.
It will take months to assess the economic damage. Preliminary estimates are often subject to wide revisions.
"We're still trying to piece together what the track and intensity it was, but the early computer model estimates are $1.2 billion to $2 billion," Chuck Watson, director of research and development at Kinetic Analysis, told CNBC.
The Moore tornado will most likely fall at No. 3 on the list between the Joplin, Mo., twister in 2011, which cost $3 billion, and the earlier Moore tornado in 1999 at about $1.5 billion, according to Gold. The most costly was a cluster of up to 100 twisters in six Southern states on the same day in April 2011, which cost $11 billion in damages.
As with most storms, the aftermath will likely produce an overall, short-term boost to the region's economy as insurance claims are paid and rebuilding begins. But many individual businesses and households may never fully recoup their financial losses.
Residents of Moore are already too familiar with the human and economic loss they've suffered, having survived a similar tornado strike on May 3, 1999.
That twister—with winds at 318 mph, the fastest ever recorded—left a path of destruction that killed 46 people and damaged or destroyed more than 8,000 homes. The 1999 tornado resulted in some 146,000 claims and $1.4 billion in insured losses, according to Robert Hartwig, president of Insurance Information Institute.
The National Weather Service said that Monday's tornado in Moore produced winds higher than 200 mph, putting it at the top of the tornado rating scale.
Most of the economic loss is a result of the obliteration of whole neighborhoods, as thousands of homes were flattened. The destruction was so complete that local crews were installing street signs so residents could locate where their homes had once been.
The town must also rebuild a school and other public facilities damaged by the storm. Utility crews were already at work Tuesday rebuilding damaged power lines.
Much of the cost will be offset by insurance and federal disaster assistance.
President Barack Obama directed the Federal Emergency Management Agency to send "all available assistance" to the disaster-hit area. Late Monday, the president declared Oklahoma a major disaster area, making federal aid available to people in Cleveland, Lincoln, McClain, Oklahoma and Pottawatomie counties.
While recent hurricanes have left some homeowners high and dry without insurance coverage, Hartwig said the survivors of the Moore twister are more likely to see their losses covered. That's because coverage for wind damage is more commonly included in homeowner policies than flood coverage, he said.
"It doesn't matter how fast the wind was or if wind blew off the roof and let water in or hail damage -- all of that would be covered whether it's a home or a business," he said.
Thanks to improvements in weather forecasting and warning systems in storm-prone communities, death tolls from twisters have been falling in recent years. The deadliest tornado on record, which struck March 18, 1925, killed 695 people in Missouri, Illinois and Indiana.
But economic losses have spiked as the frequency and severity of tornadoes and thunderstorms has surged.
"Even after you adjust for inflation, the last five years have been the five most expensive years ever," Hartwig said.
About a third of those losses came in a two-month period, in April and May 2011, when five clusters of tornadoes swept through the South and Midwest, killing 545 people and leaving a devastating path of destruction. The total cost of rebuilding came to nearly $27 billion, according to the National Climatic Data Center.
The severity and frequency of destructive storms is expected to continue.
"Whether you believe that the volatility in weather is due to natural cycles or whether its man-made, from our perspective it doesn't matter," Gold said. "The fact is there is more volatile weather today. Storms are more severe and more violent, and we have to prepare for that."
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