They cleaned out Mary Berry's office last Friday; packed her things in crates and hauled them away. It was an ignominious end to her tenure as a member of the U.S. Commission on Civil Rights, and it might have marked, just as ignominiously, an end to the commission itself.

The outspoken Berry was fired last Tuesday along with two other commission members, Blandina Cardenas Ramirez and Rabbi Murray Saltzman, effectively eviscerating the agency.

That, by the way, is no attack on the three remaining commission members: Clarence Pendleton (chairman) and Mary Louise Smith (vice chairman), both Reagan appointees, and Jill Ruckelshaus, a Carter appointee who might also have been ousted but for the fact that her husband is Reagan's EPA secretary.

The point is not that these three are wrongheaded or incompetent people but that the president, by removing the members not of his liking, has destroyed the agency's reputation as an independent body. He may have destroyed the agency itself, which, lacking a quorum, cannot even conduct its routine business.

The often-controversial commission has been struggling for survival since last May, when President Reagan first nominated three new commission members, firing (by implication, at least) the three members whose views he found increasingly incompatible with his own. Berry seems to have been a particular thorn in his side. The Senate refused to confirm the Reagan appointees, not so much because it found them unworthy as because of what Reagan's action threatened to do to the commission. A number of presidents have found the commission to be unfair to them, or insufficiently concerned about the political implications of its reports, or simply a nuisance. But no president, until now, ever fired a commissioner.

Berry and Ramirez will challenge their dismissals, on the ground that the law establishing the commission does not permit their firing except for cause.

But it may not matter that much. It's virtually inconceivable, no matter what happens in court, that the commission will be reestablished as an independent adviser to the president. Last Tuesday's action aborted efforts on behalf of a compromise proposal to enlarge the commission, making room for the Reagan nominees without firing anybody.

Backers of the commission are running out of time and ideas. Technically, the agency expired at the end of last month. But the legislation that created it calls for a 60-day phase-down period. That period ends Nov. 29, and unless Congress enacts reauthorization legislation by then, the commission is dead.

Sen. Howard Baker (R-Tenn.) has indicated that he will try this week to get some sort of reauthorization measure adopted. Pending that effort, Sens. Joseph Biden (D-Del.) and Arlen Specter (R-Pa.) have put on hold their compromise plan to turn the commission into a congressional advisory body --a compromise that may itself have constitutional difficulties.

There is even talk that President Reagan might take advantage of the Thanksgiving recess to appoint Morris Abrams, one of his three original nominees, in order to give the commission a quorum.

But this is mostly stopgap, emergency-room talk. The Civil Rights Commission has been comatose since last Tuesday. Unless someone can come up with a plan for restoring the agency to independence and vigor, it may be just as well to pull the plug.