Andrew Aiken has resigned as president and CEO of the Palm Beach Zoo.

A national search will begin for Aiken’s replacement, the zoo said Tuesday. It cited no reason for his decision to leave.

"The Board is grateful for Mr. Aiken’s leadership and for the work he has done over the last six years," said Michele Kessler, chairman of the zoo’s board of directors. "We wish him the very best."

Aiken led the zoo during the aftermath of the fatal mauling of one of its zookeepers by a Malayan tiger last year.

The mauling took place April 15, 2016, and took the life of Stacey Konwiser, a keeper who specialized in tigers.

State and federal agencies reviewed the zoo’s operations following the incident. Federal officials did not cite any workplace violations but made several recommendations to prevent furture incidents. The zoo said it "adapted substantially" those recommendations.

This is a developing story. Check back for updates.