This post has been updated with a statement from Metro officials.

The Federal Transit Administration on Monday informed Metro it will now be responsible for overseeing safety of the transit agency’s rail system, putting on paper a first-of-its-kind action announced by U.S. Transportation Secretary Anthony Foxx earlier this month.

“We recognize the urgency of setting the transit system of our nation’s capital in much better shape,” Foxx said in a prepared statement that accompanied the letter and safety directive formalizing the arrangement. “While we will work to direct Metro into a new era of safety, our actions do not remove the need for state and local leaders to govern and prove that they can successfully execute their charge to provide safe, reliable service.”

Metro is now the first U.S. subway system to be under direct federal oversight for safety.

In taking responsibility for safety oversight of the nation’s second-busiest subway system, FTA officials acknowledged that previous efforts to hold Metro accountable for safety lapses through a state safety oversight agency known as the Tri-State Oversight Committee, have largely failed.

In her letter to Metro leadership, acting FTA Administrator Therese McMillan made clear that will change under FTA’s watch telling the transit agency’s leaders, “… it is no longer business as usual.”

“This is the strictest level of federal safety oversight ever placed on a rail transit agency,” McMillan noted.

Metro spokesman Dan Stessel said a statement issued Oct. 9, in response to Foxx’s initial announcement about FTA’s expanded role remained applicable to Monday’s developments.

“We will continue to work closely with FTA to improve safety of the WMATA system and are fully engaged in implementing corrective actions recently approved by the agency,” interim General Manager Jack Requa said at the time. ” We appreciate Secretary Foxx’s continued support and his leadership on safety oversight.”

As previously outlined, McMillan said the new arrangement will include “heightened, on-the-ground inspection activity to ensure that required actions are indeed being implemented,” as well as surprise inspections to address safety concerns that are brought to the agency’s attention.

McMillan said the agency has designated Sean Thompson, who previously worked as a deputy regional administrator for the Federal Railroad Administration, to be FTA’s point person on Metro oversight. FTA officials said Thompson already is familiar with Metro’s operations having working on the recent safety management inspection report of the transit agency.

In addition to the three-page letter, the FTA also issued a safety directive formalizing its oversight actions.

In designating FTA as the main safety oversight agency for Metro, Foxx rejected an urgent recommendation from the National Transportation Safety Board, which said that FRA, another DOT agency with more experience overseeing safety in rail systems and more resources, assume responsibility for safety at Metro.

Here is McMillan’s letter to Metro Board Chairman Mortimer Downey and Metro interim General Manager Jack Requa: