A worker on the demolition of a downtown parking garage was trapped early Tuesday when part of the concrete structure collapsed onto his tractor, and more than 100 firefighters struggled for 7 hours to free him.

The worker was conscious and talking but was seriously injured, with tons of concrete pinning his legs inside his front-end loader, said Mike Sandulak, a division chief with the Phoenix AZ Fire Department.

Firefighters used wooden shoring and air bags to stabilize the building and worked to cut reinforcing rods in the concrete so they could remove it, Sandulak said.

The 28-year-old man's father also had been working at the site, and Sandulak said he was allowed to stay close to his son while rescuers worked to free him. The man's wife and other family members also were at the scene and social workers were with them.

Firefighters gave the unidentified worker pain medication and started intravenous lines so they could give other medications and fluids, Sandulak said.

Firefighters were joined by medical personnel wearing hospital scrubs and hard hats.

The accident happened about 4:45 a.m. Tuesday during demolition work at the Civic Plaza construction site in downtown Phoenix.