James Brooks Chandler is charged with second-degree murder in the death of Philip Snodgrass.
But upgrades to help coordinate the work of ventilation fans have not moved beyond the paperwork stage.
Agency says the ventilation system was used incorrectly and smoke in tunnels can’t be pinpointed.
Sen. Barbara Mikulski (D-Md.) says first responders should be required to take training on how to conduct emergency rescues in the Metro system.
Communications became an issue during a fatal incident last month near L’Enfant Plaza.
Tests found weak or nonexistent communications, similar to what happened in the deadly incident.
Work to install “low-smoke” lines was underway but took on new urgency after the Jan. 12 incident.
But D.C. fire said it had told Metro days before that fatal incident that radios weren’t working at station.
City documents say the first responders to reach the platform had no idea hundreds of passengers were gasping for breath.
Officials have yet to explain clearly why firefighters waited at the L’Enfant Plaza station as a train carrying scores of passengers filled with smoke, leading to one woman’s death.