WMATA surveillance video inside L’Enfant Plaza Metro station on Jan. 12, 2015, shows people on the platform evacuating as smoke comes from the southbound tunnel for the Green and Yellow Lines.

The Washington area’s troubled rail system is once again being scrutinized by members of Congress, as two House subcommittees delve into Metro’s troubled finances, repeated safety breakdowns and chronic service woes. The hearing follows an unprecedented shutdown of the rail system for emergency safety inspections of cables.

Among those slated to testify are Metro General Manager Paul J. Wiedefeld and Metro Board Chairman Jack Evans. Carolyn Flowers, a senior adviser with the Federal Transit Administration, and Christopher A. Hart, chairman of the National Transportation Safety Board, are also scheduled to appear.

Here’s a look at what the four witnesses are expected to say during the hearing.

Wiedefeld is the first witness expected to speak:

2016 04 13 General Manager Paul J. Widefeld WMATA Testimony

Evans, the D.C. Council member who serves as Metro chairman, is up next:

2016 04 13 Chairman Evans WMATA Testimony

Flowers, the federal transit adviser, is next. The Federal Transit Administration is responsible for safety oversight of Metrorail.

2016 04 13 Carolyn Flowers FTA Testimony

And Hart, the NTSB chairman, will speak. The NTSB’s report on the fatal smoke incident that happened in January 2015 is expected to be released in May.

2016 04 13 Christopher Hart NTSB Testimony