Obama calls Oklahoma tornado's toll 'hard to comprehend'

MOORE, Oklahoma (Reuters) - Standing by a pile of debris that once was an elementary school, President Barack Obama on Sunday called the destruction last week's tornado wrought in Moore, Oklahoma, "hard to comprehend" and vowed to provide long-term federal help in rebuilding.

The tornado, rated at the top of a five-step scale used to measure the destructive power of twisters, killed 24 people - including seven children at the school site Obama visited. It ripped a 17-mile-long (27-km-long) corridor of destruction through the suburb of Oklahoma City, flattening entire blocks of homes, two schools and a hospital.