The chief safety officer for the MBTA is resigning at the end of this month, after three years with the public transit agency, according to a letter to employees from General Manager Phillip Eng.

Ron Ester will be resigning from his post, effective Aug. 30, Eng wrote in his memo to employees that was dated Tuesday.

"I am grateful for Ron’s service to the MBTA," Eng wrote. "He has made a real difference in the safety of our system, and he will be missed."

Eng wrote in his letter that Ester was a key part of putting into place new policies after the 2019 Safety Panel report, the MBTA's response to the pandemic and also the FTA Safety Management Inspection.

A search will get underway for Ester's replacement, and meanwhile, Eng has asked Senior Advisor for Capital, Operations, and Safety Rod Brooks to oversee the Safety Department on an interim basis.

Ester issued a statement about his upcoming departure from the T.

"I am honored to have served as Chief Safety Officer at the MBTA," he wrote. "I am proud of the work that we have done to make our system safer during my tenure, despite the many challenges that we have faced. The MBTA has been underinvested in for decades, and it has taken a lot of hard work to make our system as safe as it is today. I know that there is still more work to be done, but I am proud to have played a leading role in many of the improvements that have taken shape. It’s bittersweet to be stepping away from my role, but I know that the MBTA is in good hands with Phil Eng. I wish him and everyone at the T all the best in the future."

According to his LinkedIn profile, Ester had a long tenure with the Chicago Transit Authority — where he served as Vice President of Rail Operations and Deputy Chief of Safety, Security and Communication — before coming to the MBTA.

Hear what LivableStreets Alliance Executive Director Stacy Thompson, and others, had to say on the MBTA's chief safety officer resigning here: https://www.nbcboston.com/news/local/mbtas-chief-safety-officer-resigning-at-months-end-gm-says-in-letter/3113328/