An inmate firefighter working to contain a brushfire in Malibu Thursday morning was critically injured after a boulder falling down a steep ravine struck her.

The inmate was battling a fire that broke out around 3 a.m. Thursday morning, about three miles north of Pacific Coast Highway, close to Mulholland Highway, according to KTLA.

The woman was airlifted to UCLA Medical Center at around 7:30 a.m. for treatment of "major injuries," according to ABC 7.

Firefighters had achieved approximately 35 percent containment by 8 a.m. limiting the fire's burn area to about 7 acres, revised down from an earlier estimate of 20 acres, according to City News Service. No structures were damaged, though the fire did prompt a few evacuations throughout the Malibu hills early Thursday morning.

California first established its inmate fire-fighter program in 1946, giving inmates an opportunity to reduce their sentence time by working and living at designated correctional "fire camps" located throughout the state.

For example, in Malibu, the California Department of Corrections and Rehabilitation operates Malibu Conservation Camp #13 where 75 female inmates (likely including the one who was injured this morning) live and work. Per VICE, each day spent at the fire-camp counts as two days towards the reduction of an inmate’s sentence.

While obviously we don't have any details about the inmate who was injured this morning, we do know that human rights groups have expressed concern over potential labor-exploitation and poor working conditions.

"This is a prime example of how prison slavery undermines salaries and wages for non-prisoners," argues Paul Wright, editor of Prison Legal News and executive director of the Human Rights Defense Center, to VICE. "If they weren't having the prisoners do the work for whatever pittance they pay them, they would be paying non-prisoners 15-20 dollars an hour plus benefits."

On the flip side, inmates who work at the fire camps report, according to VICE, feeling like contributing members of society while working as firefighters. Inmates who worked as firefighters also have lower rates of re-offense, 52 percent compared to 63 percent among the general inmate population.