Toddler missing after latest outbreak in historic tornado season

Piedmont, Oklahoma (CNN) -- As the sun rose Wednesday over Oklahoma, lighting the trail of destruction left by a string of tornadoes and severe weather, members of the National Guard were already out, searching for a missing 3-year-old.

Two of the toddler's siblings were killed as the storms churned through Canadian County. Their mother is in critical condition, said Sheriff Randall Edwards.

The children are the latest victims of a ferocious and historic tornado season that has left more than 500 people dead, according to figures from the National Weather Service and local authorities.

It is the deadliest tornado season since 1953, when 519 people were killed in twisters.

Fifteen of the deaths came in the latest string of storms that passed through Arkansas, Kansas, and Oklahoma Tuesday night.

The National Weather Service Storm Prediction Center warned that storms could strike parts of the region again Wednesday.

"Thank God we weren't (there)," said Pastor Gary Rogers of the Grand Assembly of God church in Chickasha, Oklahoma, where a tornado was spotted Tuesday night. "No one was there." Half the church's roof was torn off, he said.

Twenty-four hours later, the church would have been bustling with Wednesday activities, he said.

Chickasha is about 40 miles southwest of Oklahoma City.

The tornado "came right past the store," said Chickasha AutoZone employee Nathaniel Charlton. "They had a little debris thrown across the parking lot. It was on the ground, but it wasn't bad."

The tornado that passed through Chickasha also damaged several other communities.

The 15 deaths include 10 in Oklahoma, three in Arkansas and two in Kansas, authorities said.

Seven people were killed in Canadian County, Oklahoma, Sheriff Edwards said.

Two people died in Oklahoma's Logan County and one was killed in Grady County, according to Cherokee Ballard with the state medical examiner's office.

In Arkansas' Franklin County, a tornado touched down shortly after midnight, killing at least two people, according to Tommy Jackson, a spokesman for the Arkansas Department of Emergency Management.

"We could see debris in the radar returns we were receiving, and that gave us a good indication the tornado was strong and large," said Steve Piltz, a forecaster with the National Weather Service in Tulsa, Oklahoma, adding the tornado was anywhere from a half-mile to a mile wide.

A third death was reported in the Johnson County town of Horseshoe Bend, according to Arkansas' emergency operations center.

In Stafford County, Kansas, two motorists died when an uprooted tree slammed into their van, according to the state adjutant general's office.

The powerful storms also paid a visit to Joplin, Missouri, where a weekend tornado killed more than 120 people, making it the deadliest single U.S. twister since modern record-keeping began 61 years ago.

Joplin is not expected to face severe storms Wednesday, but could get thunderstorms, according to the National Weather Service.

The city was briefly under a tornado warning late Tuesday before it was raked by blustery winds and peppered with lightning.

Twisters also brewed in Dallas and several northern Texas counties, according to the National Weather Service.

The storms disrupted air traffic, and could have ripple effects for air travel in parts of the country throughout Wednesday.

About 10,000 people slept in Dallas-Fort Worth Airport overnight, having been stranded by the storms, said airport spokeswoman Sarah McDaniel. Passengers and staff were forced to evacuate to designated shelters inside the airport as storms moved in, she said.

American Airlines and American Eagle had approximately 65 aircraft pulled from service due to weather damage Tuesday night, McDaniel said. Nearly 100 flights were canceled as of early Wednesday, she added. "Some airlines are still assessing hail damage."

Southwest Airlines said Wednesday that it took eight aircraft out of service in Dallas for inspections and repairs due to damage from the weather, particularly the large hail.

Operations at Love Field in Dallas were suspended for a time Wednesday night, said spokesman Jose Torres. The airport moved all passengers and personel into an airport basement for an hour as winds kicked up and power was lost, Torres said.

When people emerged from the basement, they found damaged aircraft and vehicles. Some passengers slept in that airport as well, Torres said.

The storms left a wide swath of destruction.

Edwards said Piedmont, Oklahoma, was especially hard hit. "There's more damage in Piedmont because it's the most densely populated area."

A large tornado crossed I-40 near El Reno, destroyed residences and caused a gas leak at an energy plant west of the state capital, Edwards said.

Twenty workers were injured at a drilling rig, according to El Reno City spokesman Terry Floyd.

The twister injured motorists on I-40 and U.S. 81, Canadian County Emergency Management Director Jerry Smith said. There were reports of property damage in the area.

About 1,200 people packed a shelter in Newcastle, a bedroom community near Oklahoma City, during the storm, said city manager Nick Nazar. "That saved lives."

About 100 people were displaced, and 50 homes were rendered uninhabitable, Nazar told CNN. Two or three businesses were damaged, as was an elementary school.

Statewide, at least 60 people were hurt and nearly 58,000 homes lost power, according to the Oklahoma Department of Emergency Management.

Some employees at the Storm Prediction Center in Norman, Oklahoma, briefly took shelter as a tornado approached, a spokesman for the National Weather Service told CNN.

Emergency personnel were mobilized in the immediate aftermath of the storms, Oklahoma Gov. Mary Fallin said.

"The National Guard is out helping, our highway patrol, our health department, Salvation Army, Red Cross, all of our first responders are out across the state," she said, noting the massive outbreak of tornadoes that lasted most of Tuesday evening.

"I've been in (public) office for 20 years. I've been through a lot of these natural disasters, but I've never seen this many in a short period of time."