Investigators are focusing on a delivery of cinderblocks as being the cause of a steel roof collapse at a Fort Greene construction site.

Officials say a 67 year old worker died, after falling 40 feet to basement. It happened around 9 this morning before work even started on the site.

"It was clear the floor the blocks were delivered on were not structurally stable and could not handle the load," said Department of Buildings commissioner, Robert LiMandari.

Officials say five workers were on the interior roof of the half built building when the blocks were delivered. Without warning, the roof caved in. Three workers jumped to an adjoining building. A second worker who fell to the basement is recovering from his injuries at Kings County hospital.

"I watched as they were trying to revive him," said Victoria, who lives across the street.

Neighbors say they weren't shocked and say the collapse was an accident waiting to happen.

"You're putting several hundred pounds in a concentrated spot, it's going to flex steel," said Ted Johnson who sees the site on his way to the park.

Alex Sichel, who lives two doors down, said calls to 311 were made about excessive vibrations coming from the area. But no formal complaint was made or violations issued.

"We've been trying to get their attention for them to see what's wrong," said Sichel.

Profession Grade Construction applied for permits to build on the site back in February to build five two-family homes back in February. While investigators try to pinpoint a cause of the accident, work will be stopped.

"Until we pinpoint a cause, they won't go back to work," said LiMandari.