The department's Facebook page identified the fallen firefighter as Larry Gressett.
"This is a tragic loss to each of the families who served with and who were friends with Larry and his family," a post from the department on the page reads. "Please continue to be in prayer for Larry's family and his fellow firefighters, who are completely grief-stricken."
Crews responded to the call at a private pond in Toomsuba at approximately 5:30 p.m. to find a man in a boat trying to hold the head of his drowning friend out of the water.
"He indicated that the gentleman had fallen into the lake and was attempting to get to the shore," Lauderdale County Chief Deputy Ward Calhoun told WTOK-TV. "He then reappeared and surfaced two minutes later. At that time, he was unresponsive."
That is when firefighters arrived on the scene.
Gressett went in after the unresponsive man, but had to be rescued and was declared dead along with the man who he was trying to save.
The Mississippi Department of Wildlife, Fisheries and Parks will conduct an investigation.