A 11-storeyed under-construction building collapsed in a city suburb today and several persons are feared trapped under the debris, a top Fire and Rescue Services official said.

“11 floors seem to have been completed so far. The building collapsed suddenly according to statement of eyewitnesses,” Fire and Rescue Services Joint Director, S Vijayasekar said.

One worker has been rescued he said, adding ambulances, doctors and paramedical personnel were on the spot.

Twelve fire tenders and 100 personnel were involved in the rescue work, he said.

The incident occurred at Moulivakkam near Porur in the western suburb, about 20 km from here, as rains lashed the area and several other parts of the city this evening.

Asked if rains could also have been a factor in the collapse of the building, the official said “it does not seem to be due to the rains… we have to see.” On the number of trapped workers, he said “it is not possible to categorically comment on it… eyewitnesses say that there were about 50 construction workers at the time of the collapse.”