(CNN) A United States postal service worker was shot and killed while making deliveries in Louisiana, authorities said.

The postal worker, identified as Antonio Williams, 52, was shot Saturday morning in Shreveport, according to Caddo County spokesman John Prime.

He was making deliveries around 11:20 a.m. when the attack happened, and was declared dead at the hospital.

Shreveport Police and federal authorities are investigating the shooting.