MOORE, OK (RNN) - Gov. Mary Fallin said Tuesday officials did not know how many people were still missing but planned to continue looking through the devastation caused by a massive tornado.
"We will go through every building and every piece of debris," Fallin said.
In a 12:20 p.m. CT news conference, she described what she saw during an aerial tour of the affected area. The tornado, with winds up to 190 mph, cut a 17-mile stretch as wide as two miles through the Oklahoma City metro area.
"It's hard to look at," she said. "The big challenge for us is determining where to begin. The streets are gone."
The Oklahoma Medical Examiner's Office revised the death total from the estimated EF-4 storm from 51 to 24 Tuesday.
Amy Elliot, chief administrative officer for the medical examiner's office, said the original count had been reported during early phases of the recovery effort.
"To date, 24 deceased victims of the tornado have been transported to our Oklahoma City office," she stated via email. "Positive identifications have been made in the vast majority of those, and these are ready for return to their loved ones."
Nine of the dead were children; seven were found at an elementary school directly hit by the storm. All of the victims resided in the Moore area.
CNN reported at least 237 people had been injured.
In a Tuesday news conference, President Barack Obama said he told senior staff Oklahoma should get everything it needed "right away." He encouraged people who want to help to go online to the American Red Cross.
"We recognize you face a long road ahead ... but you will not travel that path alone. Your country will travel it with you," he said.
Oklahoma Department of Emergency Management representative Terri Watkins said 101 people had been found alive and rescued, CNN reported. But the death toll is expected to rise as emergency crews continue their search.
Earlier, the medical examiner's office said it expected to see around 40 additional bodies, half of them children.
The National Weather Service reported the tornado had wind speeds up to 200 mph.
Rescuers worked all night searching the debris for survivors, with particular attention focused on Plaza Tower Elementary, one of two elementary schools destroyed by the twister.
"They're pressing forward. Hopefully we'll hear just some glimpse, and we can help some child … help some grownup," James Dickens, a rescue worker, told CNN early Tuesday morning.
Children and personnel at the other elementary school in the storm's path, Briarwood Elementary, were all safe and accounted for Monday.
The local hospital, Moore Medical Center, was also demolished by the tornado, with all there reported safe. Vehicles were seen piled up in the parking lot, with red Xs denoting the vehicles had been searched.
President Barack Obama declared the scene a disaster area Monday, allowing the release of federal emergency funds to help with the town's recovery.
Oklahoma Gov. Mary Fallin activated the National Guard and said crews were "trying to make sure we have looked under every single piece of debris" for trapped victims.
Among the organizations mobilizing were Task Force One of Tennessee and Texas, urban search and rescue teams, WMC-TV and KLTV reported.
The city of Joplin, MO, which suffered its own devastating tornado two years ago, sent official assistance Monday night.
"We remember the amount of assistance that we received following the tornado two years ago, and we want to help others as they helped us. We know too well what their community is facing, and we feel an obligation to serve them as they have served us," said Joplin City Manager Mark Rohr in a statement.
Country singer Toby Keith, who hails from Moore, reflected on the tragedy in a released statement.
"This storm has devastated the community that I grew up in," he said. "I rode my bike through those neighborhoods. I have family and friends in Moore. My heart and prayers go to those that have lost so much. But Moore is strong, and we will persevere. God be with you all."
According to the Facebook page Moore Oklahoma Tornado Info, more than a hundred horses were killed and many were injured. Volunteer veterinary assistance was on hand.
The American Red Cross started accepting donations to aid in their response. Donations can be made a www.redcross.org/okc or by texting REDCROSS to 90999.
To donate $10 to the Salvation Army, text STORM to 80888 or visit https://donate.salvationarmyusa.org/uss/eds/aok.
To search for missing relatives or to register yourself as safe, visit safeandwell.org.