Oakland firefighters rescued a contractor after concrete from an East Oakland duplex's foundation came loose, trapping him in this trench Sunday morning. (Courtesy Oakland Fire Department) ( George Kelly )

OAKLAND -- A contractor is expected to sustain only minor injuries after firefighters rescued him from a trench that collapsed next to a house Sunday morning, officials said.

Shortly after 10:30 a.m., firefighters received word of a person trapped in a trench in the 1700 block of East 20th Street, Oakland fire battalion chief Dino Torres said.

Thirty-three firefighters, including at least three engines, a truck, a rescue unit and three battalion chiefs, responded within four minutes, Torres said.

The contractor was digging a trench beside the duplex house when the foundation gave way, sending chunks of concrete onto him and trapping him. After conferring with city engineers who determined the house was still stable and habitable, firefighters carefully cleared concrete away over the next hour and fifteen minutes, Torres said.

Firefighters removed the man just before noon and took him to Highland Hospital while treating him for "crush syndrome" symptoms as a precaution, while others cleaned up the scene over the next half-hour, Torres said.

"The crews did a great job of shoring it up and coming up with a quick plan to move the concrete," Torres said. "It took a lot of coordination, a lot of teamwork, and it went really well."

The contractor is expected to sustain only minor injuries, Torres said: "It could have been a lot worse."

Contact George Kelly at 408-859-5180 or follow him at Twitter.com/allaboutgeorge.