Updated

An emergency official says four people were crushed to death and 25 rescued from the rubble when a four-story building under construction collapsed in the Nigerian economic center of Lagos.

General manager Femi Oke-Osanyintolu of the Lagos State Emergency Management Agency said Tuesday they had sealed off the building site on upmarket Victoria Island.

Several workers injured when the top floor of the building collapsed on Monday have been hospitalized.

Such accidents are frequent in this West African nation where corruption is endemic and building contractors often use inferior products and cut corners. Dozens of people have died in collapsed buildings this year.