Rescue workers are seen at the site of a collapsed 21-story apartment building under construction in Lagos, Nigeria, Monday, Nov. 1, 2021. At least two people were killed and dozens more remain missing after the collapse of a 21-story apartment building being built in an upscale area of Nigeria’s largest city, witnesses said on Monday. (AP Photo/Sunday Alamba)

A 21-story apartment building being built in an upscale area of Nigeria’s largest city collapsed on Monday with dozens of workers feared trapped under the rubble, witnesses said.

Construction worker Eric Tetteh, 41, said construction teams were waiting for an excavator to arrive at the site when the building suddenly crumbled into a heap of debris.

“Me and my brother, we escaped, but more people are there _ more than 100 people,“ he told The Associated Press.

Obafemi Hamzat, deputy governor of Lagos, was met on his arrival at the site by angry youths who accused authorities of failing to immediately launch rescue efforts.

“For the past two hours since it collapsed nobody came here,“ one angry worker shouted towards him.

Workers said the high rise, which collapsed in the Ikoyi area of Lagos, had been under construction for about two years.

It was not immediately known what caused the collapse. However, such incidents are relatively common in Lagos because enforcement of building code regulations is weak. Other observers blame shoddy work by private developers eager to meet demand for housing in the megacity.