What’s being called a monster  tornado at least a half-mile wide roared through the Oklahoma City suburbs Monday afternoon, flattening entire neighborhoods and destroying an elementary school, as teachers and children huddled against the storm.   Rescuers launched a rescue effort at the school, pulling children from heaps of debris and carrying them to a triage center.

At least 51 people were killed, including at least 20 children.  The search is still on for survivors.

The storm destroyed building after building in Moore, a community of 41,000 people about 10 miles south of the city. Block after block lay in ruins. Homes were crushed into piles of broken wood. Cars and trucks were left crumpled on the roadside.

The National Weather Service believes  the tornado was an EF-4 on the enhanced Fujita scale, the second most-powerful type of twister.

Amy Elliott, spokeswoman for the Oklahoma Medical Examiner's Office, told The Associated Press early Tuesday that officials could see as many as 40 more fatalities from the tornado.

Read more from the Associated Press.