[Updated at 6:50 p.m. ET]
Many parents were able to get their children out early on Monday from Plaza Towers Elementary School in Moore, Mayor Glenn Lewis said. "Unfortunately, not everybody did," he added.
Plaza Towers was one of two elementary schools hit by the twister. But unlike Plaza Towers, Briarwood Elementary School had no fatalities. It was a "newer model" of schools and had a "safe room" -- as is required since a 1999 tornado for newly constructed schools -- while Plaza Towers did not, Lewis explained.
[Updated at 6:46 p.m. ET]
President Barack Obama has called Oklahoma's governor "several times" and promised the federal government would do everything in its power to help those affected by the tornado, Gov. Mary Fallin told CNN's Wolf Blitzer.
She said she's also gotten calls and offers of help from Cabinet secretaries as well as "about 25 governors."
[Updated at 6:33 p.m. ET]
Speaking about the tornado rescue and recovery effort in Moore, Oklahoma, Mayor Glenn Lewis said late Tuesday afternoon that "we don't have anybody missing."
[Updated at 6:09 p.m. ET]
Moore resident Billy Verge recalled huddling in a closet with his wife and "the whole house started shaking, shaking, shaking, rocking, shaking for two, three minutes."
"I really didn't think we were going to make it," his wife, Melody Verge, told CNN's Wolf Blitzer. "I just heard it roaring."
[Updated at 5:51 p.m. ET]
The city of Moore urged those seeking to help its residents to make "financial donations only, until when and if other types of donations are requested."
The Oklahoma community's government also appealed for volunteers to help with a cemetery cleanup on Wednesday morning.
[Updated at 5:21 p.m. ET]
A host of celebrities -- many of them with connections to Oklahoma, some even to the hardest-hit areas -- are voicing condolences, tributes and messages of strength in the wake of Monday's tornado.
Country singer Reba McEntire -- writing from Cape Town, South Africa -- said that some of her relatives could hear the rumble from their storm cellar as the twisters passed by about three miles away.
Actress Alfre Woodard spoke highly of her native state, and urged people everywhere to help.
"I know firsthand the resilience of the people," she said. "They are a community-based culture and will reach their hands out to their neighbors. I trust all Americans will catch that spirit and reach out to Oklahoma now."
[Updated at 5:07 p.m. ET]
Bad weather remained a problem Tuesday in Oklahoma, according to a tweet from Will Rogers International Airport. The airport said "weather continues to impact flights," adding that "lightning (is) causing delays."
[Updated at 4:50 p.m. ET]
Insurance claims will likely top $1 billion, Kelly Collins of the Oklahoma Insurance Department tells CNN. That cost would be higher than that from the May 3, 1999, tornado that hit the same area.
[Updated at 4:49 p.m. ET]
A fund has been established to help those affected by this week's severe weather in Oklahoma -- the OK Strong Disaster Relief Fund -- Gov. Fallin says. The fund will assist those affected by the May 19 twister near Shawnee and a more powerful one the next day in Moore.