Children among 51 dead as massive tornado smashes Oklahoma City A MONSTER tornado with winds up to 320km/h and 1.6km across has smashed Oklahoma City, killing more than 50, wiping out entire neighbourhoods, crushing schools and causing pile-ups on highways as residents scrambled for safety. The Oklahoma Medical Examiner's Office says 51 people have been killed by the tornado that hit suburban Oklahoma City. Several children are among the dead. The death toll was expected to rise, an Oklahoma Medical Examiner's Office spokeswoman said. Rescuers swarmed the debris as darkness fell. More than 140 people were being treated at hospitals, including about 70 children. Some were in critical condition. Watch the latest video at video.foxnews.com "Hearts are broken" for parents looking for their children, Governor Mary Fallin told a news conference. The storm of rare ferocity - less than 1 percent of all tornadoes reach such wind speed - ripped through scores of buildings in the suburb of Moore in a region of the U.S. known as Tornado Alley. Block after block lay in ruins. Cars and trucks were left crumpled. The National Weather Service issued an initial finding that the tornado was an EF-4 on the enhanced five-point Fujita scale, the second most powerful type of twister. In video of the storm, the dark funnel cloud could be seen moving slowly across the landscape, scattering shards of wood, pieces of insulation, shingles and glass over the streets. The focus quickly turned to Plaza Towers Elementary School, where the storm tore off the roof, knocked down walls and turned the playground into a mass of twisted plastic and metal. Rescue workers passed them down a human chain to a triage center in the parking lot. Oklahoma tornados: a child is pulled from the rubble of the Plaza Towers Elementary School in Moore, Oklahoma, and passed along to rescuers after a tornado as much as 1.6km wide with winds up to 320 kph roared through the Oklahoma City suburbs, flattening entire neighborhoods, setting buildings on fire and landing a direct blow on an elementary school. James Rushing, who lives across the street, heard reports of the approaching tornado and ran to the school, where his 5-year-old foster son, Aiden, attends classes. Rushing believed he would be safer there. "About two minutes after I got there, the school started coming apart," he said. The students were put in the restroom. After the tornado passed, Tiffany Thronesberry said she got a panicked call from her mother, Barbara Jarrell. My house is on top of me! Downed power lines and open gas lines posed a risk, Police Capt. Dexter Nelson said. The same suburb was hit hard by a tornado in 1999. That storm produced the highest winds ever recorded near the Earth's surface - 302 mph (486 kph). "Oklahoma City has had more tornado strikes than any other city in the United States," the city government's website says. President Barack Obama called Fallin to express his concern. Four killed sheltering in 7-11 Four people were killed after a tornado flattened a 7-11 near Fourth St and Telephone Rd in Moore, including a mother and her baby, KFOR reports. They were apparently trying to shelter in a freezer inside the store. The victims' bodies were being sent to Oklahoma's office of the chief medical examiner, Elliott told CNN, confirming the tornado's first fatalities. Fox News reports emergency crew have now turned their attention to retrieving the bodies of at least 24 pupils. Oklahoma tornados: a series of devastating tornados have hit Oklahoma. The storms leveled Plaza Towers Elementary School and Briarwood Elementary School in Oklahoma City. Photo: KWIN Oklahoma/Twitter Moore Medical Center in Oklahoma was evacuated after it sustained damage, a hospital spokeswoman said. All patients were being evacuated to Norman Regional Hospital and Health Plex Hospital, and residents injured in the storm were being told to go to those centers as well. Crews were heading to the north-south highway to start the cleanup process. More than 38,000 electricity customers in Oklahoma are without power, according to local power providers. The tornado touched down around 2.42pm Monday local time (6.42am Tuesday AEST). Oklahoma tornados: a woman is pulled out from under tornado debris at the Plaza Towers School after a tornado as much as 1.6km wide with winds up to 320 kph roared through the Oklahoma City suburbs, flattening entire neighborhoods, setting buildings on fire and landing a direct blow on an elementary school. The tornado created a huge funnel cloud, kicking up dust and debris. Moore, an Oklahoma City suburb,was the worst hit and all but wiped out, with emergency crews racing to the scene to help find survivors. Tornado came after earlier twisters caused devastation Oklahoma tornados: A fire burns in the Tower Plaza Addition in Moore following a tornado as much as 1.6km wide with winds up to 320 kph roared through Oklahoma City flattening entire neighborhoods and landing a direct blow on an elementary school. Oklahoma tornados: a boy is pulled from beneath a collapsed wall at the Plaza Towers Elementary School following a tornado in Moore, Oklahoma. A tornado as much as 1.6km wide with winds up to 320 kph roared through Oklahoma City flattening entire neighborhoods and landing a direct blow on an elementary school. Oklahoma tornados: A woman carries her child through a field near the collapsed Plaza Towers Elementary School in Moore, Oklahoma after a tornado as much as 1.6km wide with winds up to 320 kph roared through the Oklahoma City suburbs, landing a direct blow on an elementary school.