LAS VEGAS -- Five construction workers at McCarran Airport were trapped within a massive cylinder of steel rods when the structure collapsed Tuesday morning.

All five workers were hospitalized, two with critical injuries. Officials said injuries ranged from a broken hip to a punctured lung. Fellow workers cut a hole in the cage to pull them out.

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The rebar cage, part of a roadway support structure, is one of more than 1,400 constructed for the airport’s new international terminal. McCarran spokesperson Randy Walker said the cylinder was about 6 feet in diameter and was horizontal on the ground when the structure collapsed.

“Obviously we need to find out what was different about this one,” Walker said in a morning news conference.

When completed, Walker said, the cylinders can weigh as much as 30,000 pounds.

None of the injured workers have been identified, although Walker said they worked for the Pacific Coast Steel company. Walker said construction will continue at other areas of the site. The $2.4 billion terminal, also known as Terminal Three, is expected to be open to the public in 2012.

This is not the first accident at the construction site. In February, another worker, 25-year-old Byron Souza, was killed at the site. Souza was an employee of Las Vegas Paving.