The L.A. County Fire Department received a call to the BP Carson Refinery at 2350 E. 223rd Street at 7:51 a.m.
According to BP, a longtime employee was fatally injured at a rail car loading facility. An Urban Search and Rescue Team extricated the body.
The victim's name has not been released pending notification of next of kin.
The rest of the refinery was operating normally after the accident, BP said in a statement.