Summary

This live blog on the tornado in Moore, Oklahoma, has closed. Below is a summary and further down you can read all the developments in chronological order. Coverage of the tornado continues on the Guardian website.

• 51 people have been killed after a tornado hit Moore, a suburb of Oklahoma City. At least seven children are among the dead, with pictures from the scene showing a school severely damaged by the storm. As night fell in Oklahoma a spokeswoman for the medical examiner's office said the death toll was expected to rise.

• More than 140 people have been treated at hospital. Around 70 of those were children. Plaza Towers Elementary School, was particularly hard hit. The storm tore off the roof and knocked down walls. Several children were pulled alive from the rubble, the Associated Press reported.

• Oklahoma governor Mary Fallin said "hearts were broken" following the storm. In a news conference she said emergency services were doing all they could to find survivors. She asked people to stay away from the damaged areas to allow authorities to continue their search.

• The National Weather Service said the tornado reached up to a half-mile wide. They rated the tornado as an EF-4 on the enhanced five-point Fujita scale; the second most powerful type of tornado. Video footage showed a dark column moving slowly across Moore for more than 30 minutes.

• Footage from the ground shows entire streets and blocks were raised to the ground. Video posted to Vine and elsewhere showed people searching through large piles of wreckage. Emergency crews warned of gas leaks in the area.