This article was produced in partnership with the Pulitzer Center on Crisis Reporting.

WASHINGTON — Next year is the 20th anniversary of the Sept. 11, 2001, hijackings that killed 2,976 people in New York, at the Pentagon and in a Pennsylvania field. For much of those two decades, the United States has been holding five men accused of helping plot the attacks.

But they have yet to come to trial. The military’s legal proceedings at Guantánamo Bay, Cuba, have lurched from setback to setback, disappointing the families of the victims who have watched in frustration and dismay. Then over the summer, a military judge finally set a timetable toward a trial that envisioned a start date early next year.

Now, that schedule has suffered a one-two punch that promises more delay. First, the coronavirus crisis has cut off most access to Guantánamo Bay, complicating the work of the prosecutors, defense teams, judiciary and support staff who shuttle between the base and the mainland. Then the judge abruptly announced last month that he was retiring from the Air Force and would leave the case next week.

Most pretrial work, including legal meetings, is on hold. The prison at Guantánamo does not allow the five defendants to meet with their lawyers by telephone or video link.