MOORE, Okla. - President Obama visited tornado-devastated Moore, Okla., on Sunday, consoling people staggered by the loss of life and property and promising that the government will be behind them "every step of the way."

"I'm just a messenger here," the president said, adding that "folks are behind you" across America. He offered moral and monetary support in the wake of the monstrous EF5 tornado that killed 24 people, including 10 children, last Monday.

Standing with Gov. Mary Fallin and other state and federal officials, Obama noted a substantial rebuilding job ahead and said that "our hearts go out to you."

"This is a strong community with strong character. There's no doubt they will bounce back," he said. "But they need help."

The White House said the Federal Emergency Management Agency has already provided $57 million in rebates and incentives to help build about 12,000 storm shelters in Oklahoma. "These storm shelters can be the difference between life and death," presidential spokesman Josh Earnest told reporters accompanying Obama to Oklahoma on Air Force One.

Once on the ground, Obama urged the American people to make contributions, saying the damage was "pretty hard to comprehend."

Obama rode past grassy fields strewn with debris. His first stop was the site of the demolished Plaza Towers Elementary School, where seven students were killed when the tornado turned the one-story building into a heap of bricks, broken concrete, and twisted metal.

"I know this is tough," he told superintendent Susie Pierce as he gripped her hand. As he walked, the school was on his left and on his right, homes as far as the eye could see were reduced to rubble. Vehicles were turned upside down, toys were strewn about with with furniture and ripped out wall insulation. Every tree had been stripped of leaves and bark.

Obama later met privately with victims' families at Moore Fire Department Station No. 1, which has turned into a command center with dozens of first responders sitting at folding tables where fire trucks are normally parked. "I know this is tough," he told superintendent Susie Pierce as he gripped her hand.

Obama was greeted first at Tjinker Air Base near here by Fallin, who had said earlier she appreciated the visit, but that her state also needed quick action from FEMA. She said that so far, the agency has done a great job of speeding relief and cash assistance.