It happened at a newly constructed home in the 1000 block of Stratford Avenue just after 9 a.m.
Officials said the 35-year-old worker was trapped in the basement of the home after a wall collapsed, causing him to suffer injuries to his legs.
A secondary collapse happened after first responders entered the home to rescue him.
"His lower extremities up to his knees were buried in debris from the foundation that collapsed and also under the secondary collapse as well," said Bridgeport Fire Department Chief Lance Edwards.
That made a difficult rescue even more challenging because it now required firefighters to shore up the foundation -- for their protection and the trapper worker as well.
"We were essentially building new pillars and columns underneath the existing rafters to prevent further collapse," said Bridgeport Fire Department Lt. Gregory Prior. "He was fully underneath the foundation.So he couldn't move anything. He couldn't help us out. It was just a slow digging process."
The worker was rescued just before 1 p.m. His injuries are considered serious, but not-life-threatening.
Bridgeport Mayor Joe Ganim said workers had the proper permits to renovate the empty multi-family building, which caught fire several years ago.
The home does not have a certificate of occupancy and now with OSHA investigation a pair of collapses in the home's basement, there won't be tenants there any time soon.
"As serious and as somber as this whole thing is, it is at this point a very happy ending to what could have been a very terrible tragedy," Ganim said.
The exact cause of the collapse remains under investigation.
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