Seven construction workers were killed, 50 were injured and many more were feared trapped under the rubble after the roof of a cement factory warehouse collapsed in Mongla of Bagerhat yesterday.

The 42-foot high under-construction building of Sena Kalyan Sangstha caved in around 1:00pm when the workers were pouring concrete for the roof.

Injured worker Masud Kazi said they were pouring concrete on the roof and they had completed more than half the job.

“Suddenly, everything broke down,” he said, adding that there might have been problems in setting up of the scaffolding.

The injured were admitted to the Mongla Port Authority Hospital, Rampal Upazila Health Complex, and Khulna Medical College Hospital, Superintendent of Police Nizamul Haque Molla of Bagerhat told The Daily Star over the telephone at 7:00pm.

Three of the deceased were identified as Amir Akunji and Maruf Hawlader of Rampal upazila in Bagerhat, and Al Amin of Bagmara in Rupsha upazila of Khulna.

Identifies of the rest could not be known.

Members of the Coast Guard, the Navy, the Army, the police and the fire brigade were conducting the rescue operation cordoning off the 4062sqft warehouse. 

It was difficult to estimate the number of workers trapped under the rubble or how many were released after primary treatment, rescuers said.   

Awal, a worker, who luckily escaped the accident, said as many as 180 workers were working in the building when the roof collapsed.

Most labourers were hired from Rupshaghat in Khulna yesterday for the construction of the warehouse roof, he said.

An official of Sena Kalyan Sangstha, however, said the number of workers could be over 90.

Joynal Abedin, in charge of fire service in Bagerhat, said, “A good number of more workers might be stuck under the debris.”

“The rescue operation will continue as long as workers are believed to be trapped under the debris,” SP Nizamul said.

The official of Sena Kalyan Sangstha said it was an extended building of Mongla Cement Factory, one of the biggest industrial units of Sena Kalyan Sangstha. The building is on the Passure river near Mongla Port.

Sena Kalyan Sangstha's secretary told The Daily Star over the phone that the contract for the construction was awarded to China National Building Material (CNBM) Company Ltd through an international tender.

ITCL, a local construction company, was building the roof as a local agent of the Chinese company.

“The scaffolding for the roof might have been weak causing the collapse,” a Sena Kalyan Sangstha official speculated.

Asked for reasons behind the accident, ITCL site engineer Rafiqul Islam declined to comment.

The warehouse was scheduled to be handed over to Sena Kalyan Sangstha in November this year.

Sena Kalyan Sangstha Mongla Cement Factory's Deputy Director General Captain Syed Helal Hossain said they had formed a three-member committee to probe the accident.