SAN ANTONIO -

A worker's leg had to be amputated when he became trapped in a machine at the Bates Container facility in the 10600 block of Fischer Road on San Antonio's Southwest Side.

The accident happened around 9 p.m. Monday. Bates Container makes cardboard boxes at the facility.

The worker was operating an industrial belt pulley and mistakenly stepped in an area where he was not supposed to, according to Guy Sanders, a vice president for Bates who leads the San Antonio division.

"Basically, he was entrapped between two large rollers, and we had to get him out of the two rollers," said San Antonio Fire Department Battalion Chief of Special Operations Walter Yates.

First responders were not equipped to free the worker from the machine, so a team from San Antonio AirLife, the San Antonio Fire Department and a trauma surgeon from University Hospital went to Bates Container.

"What we're able to do is -- with specialized equipment and specialized trauma team -- bring a surgeon out to the scene and care for the patient, as well, directly on the scene, and assist in stabilization and transportation of patient," Dr. Craig Manifold, EMS director for the San Antonio Fire Department, said.

It took the surgeon 15 to 20 minutes to remove the worker's leg above the knee.

Manifold said the worker was taken by AirLife to University Hospital in critical but stable condition. Family members said his condition has been upgraded.

Sanders said Bates had all proper safety measures in place. Employees said they have to go through on site training at Bates.

"We have safety orientation and stuff like that. We usually do really well in the back, but accidents happen," one employee said.

Sanders said for now, the company is focused on helping the employee heal.

For a list of recent stories Jenna Hiller has done, click here.