A 16-foot section of the historic West Front of the U.S. Capitol broke loose and crumbled to the ground Wednesday night, creating an eyesore and yet another opportunity to focus public attention on the long-running controversy over how to restore the deteriorating west front.

George M. White, architect of the Capitol, said the collapse posed no serious danger to the structural integrity of the building--the roughly 16 pieces of sandstone that fell were part of the Capitol's facade. There were no injuries.

But at a news conference yesterday, White and two congressmen, in the finest Capitol Hill political tradition, used the incident to dramatize what they said was a need to repair the West Front by showing reporters the rough brick and stone wall that was exposed when the facade parts fell.

White and Reps. Vic Fazio (D-Calif.) and Jerry Lewis (R-Calif.) also took the opportunity to push their hotly debated proposal that calls for extending and enlarging the West Front at a cost of more than $70 million--a plan that is strongly opposed by historic preservationists and the American Institute of Architects.

On Tuesday, a House Appropriations subcommittee chaired by Fazio approved White's expansion plan.

The West Front, the side facing the Washington Mall and downtown Washington, was used as a backdrop for President Reagan's inaugural in 1981.

White's proposal would extend the now recessed portions of the West Front and make them flush with the existing broad terrace that spans the Capitol building. These extentions would improve the West Front's structural supports and add office space for congressmen and their staffs near the Senate and House chambers, White said.

The proposal also would preserve the wall of the current West Front by converting it to an interior wall inside the new addition, which White said showed his sensitivity to historic preservation needs.

But the AIA and preservationists disagree saying that White's proposal would drastically change the West Front's appearance making it flat and architecturally uninteresting.

These opponents also said that the expansion plan would be a serious blow to historic preservation efforts at the Capitol because encasing--"entombing" as they put it--the present West Front's wall inside a new structure is not a valid historic preservation method. The West Front, the oldest visible part of the Capitol building, was constructed in sections between 1800 and 1827.

Instead, the AIA and preservationists propose renovating the present West Front by replacing the cracked sandstones and improving the internal structural support system. White estimates that proposal would cost $66 million, about $7 million less than his. Preservationists say the cost is much less.

Standing near the fallen stones, Fazio said, "This is what we have been predicting for a number of years. Something needs to be done."