A strong smell of gas was detected in the building before the incident. An electrician called to inspect the boilers was killed in the explosion.

It was like an earthquake, I thought a bomb had gone off.” That was one witness’s account of the explosion that ripped through a building in central Madrid at 2.56pm on Wednesday, at number 98 Toledo street – just a kilometer from the landmark square Plaza Mayor and 15 minutes on foot from the central Puerta del Sol.

The seven-story building was destroyed in the blast, leaving at least four people dead and 10 injured. According to source from the emergency services, all the evidence points to a gas boiler that exploded. The building in question was the Church of the Virgen de la Paloma parish center. It contains office space, a shelter run by the charity group Cáritas, a meeting room, a living room and three housing units for priests.