HANOI, Indochina -- The French fortress of Dien Bien Phu fell to overwhelming hordes of Communist Viet Minn attackers today, ending a 57-day siege.
The end of the gallant defense against overwhelming odds ivas announced officially here and in Paris where Premier Joseph Laniel gave the news to the French public.
Only the isolated artillery post, "position Isabelle," located three miles south of the main fort, still held out, the announcement here said.
The end came after a savage 20- battle in which the Communists used 20,000 men to give France its worst military defeat since World War II.
The Paris announcement by Laniel said the fortress was conquered when the Communist troops, who had been surrounding it nearly two months overran its central defenses.
The news was given by Laniel to the National Assembly.
The Reds overran the command post of garrison commander Brig. Gen. Christian de Castries, but only after the proud and hawk- nosed hero of Dien Bien Phu had his own artillery to shell his command post if the Communists took it.
The French military press chief at Saigon said Dien Bien Phu had its mission.
In Hanoi a press officer pronounced the eulogy and benediction on one of history's heroic military stands by a handful of tormented and gallent men.
"Dien Bien Phu has fulfilled the mission which was assigned to it the High Command," he said.
The fate of the estimated 9,000- man garrison, including its wounded and a lone nurse in its underground medical stations, was not immediately known.
Another 2,000 men were at "position Isabelle" which now was at mercy of the full 40,000-man force of the Reds. About half the total Communist strength was used the final assault on Dien Bien Phu, the French estimated.
The Communists had not at;, tacked the isolated "Isabelle" position recently. But it could not" hope to hold out against the full force now certain to be thrown against it.
Communist "human avalanches" delivered the coup de grace against the pitifully outnumbered defenders in an attack that began at 10 p.m. Thursday.
Post after post of the fortress was overrun by the Reds.
Five posts were overrun in rapid succession on one side of the fortress. Another fell on the opposite perimeter.
Just before the end was announced, French headquarters said the Reds had thrust their deadly pincers within 800 yards of a junction directly in the center of the flaming fortress.