WASHINGTON (AP) — The federal government has shut down at the stroke of midnight Friday. That has halted all but the most essential operations and marred the one-year anniversary of President Donald Trump’s inauguration in a striking display of Washington dysfunction.

Last-minute negotiations crumbled as Senate Democrats blocked a four-week stopgap extension in a late-night vote, causing the fourth government shutdown in a quarter century. Behind the scenes, however, leading Republicans and Democrats were trying to work out a compromise to avert a lengthy shutdown.

Congress scheduled an unusual Saturday session to begin considering a three-week version of the short-term spending measure.