By Ivana Kottasova, CNN
(CNN) — A large explosion Monday at a film and TV school building in the Czech capital Prague injured at least 55 people, city fire officials said.
Officials did not immediately say what caused it, although state-run Czech TV reported that it was believed to be a gas explosion.
The blast took place in the center of the city. It caused the first floor of the damaged building to collapse.
Buildings on neighboring streets had their windows blown out.