The destruction of a considerable part of Germany's ball and roller bearing industry at Schweinfurt, Germany, during the attack by Flying Fortresses on Thursday was announced last night by Eighth Air Force Bomber Command.
    Conservative early estimates indicated that at least one-fourth of Germany's bearing production had been knocked out, an official Air Force communique said. Crews had been told before they took off that successful completion of their mission might shorten the war by six months.
    In Washington last night Gen. Henry H. Arnold, commander of the United States Army Air Forces, said the mission ranked in importance with the Liberator's raid on the Ploesti oil fields.
    Schweinfurt's plants, Gen. Arnold said, made at least half of the ball-bearings manufactured in German-occupied Europe and 75 per cent of those manufactured in Germany itself.
    The heavy damage inflicted on the plant was shown in photographs made during the bombing, Bomber Command said last night. It was estimated conservatively that at least 50 per cent of the production in the vital plants had been stopped, thus accounting for 25 per cent of Germany's total production of ball and roller-bearings.
    The importance of the target was shown by the fierce resistance that the Germans offered. Sixty American heavy bombers were destroyed, the Eighth Air Force said, in what was described as the most severe aerial battle ever fought over Europe.

    Heavy losses had been expected, however, Brig. Gen. Frederick L. Anderson, chief of Bomber Command, said last night.
    "We had expected our losses to be heavy and they were," Gen. Anderson said, "But the damage done the enemy was much greater. Weather over the target was excellent and the bombs were concentrated on vital points in the area.
    "Results of this attack eventually will be apparent in a shortage of German tanks, planes, guns and armored vehicles on the Russian, Mediterranean and Western fronts and a slowdown in submarine construction."
    Gen. Arnold said in Washington that 60 Fortresses and 592 crew members had been lost. "At least half," he said, "are believed to be alive as prisoners of war, on the basis of past experience."
    He said that the American bombers had "encountered the most intense fighter opposition so far met over Europe."

    The attack will have "a definite effect on German war economy within a reasonably short period of time," Gen. Arnold declared.
    Two waves of bombers dropped 485 tons of bombs and 88 tons of incendiaries, he revealed.
    "It was not just a spectacular air raid. It was an engagement between large armies," he said. "In a period of a few hours we invaded German-held Europe to a depth of 500 miles, and socked and crippled one of her most vital enterprises.
    "We did it in daylight with precision, aiming our explosives with the care and accuracy of a marksman firing a rifle."
    President Roosevelt, speaking to newspapermen at his press conference, called the Schweinfurt losses "serious" and asserted that the Eighth Air Force could not afford such losses regularly, but on the credit side of the ledger, he said, was the great damage inflicted on one of Germany's vital war industries.
    The loss of 60 planes was the largest toll the Germans had yet exacted in a single mission. However, the Eighth Air Force reported that 104 Nazi planes were destroyed and 55 probably destroyed. Of the 104, Fort crews claimed 91 and escorting P47 Thunderbolts 13. The P47s protected the bombers on their way in and on their way out.
    Despite the relatively high losses, civilian correspondents reported that the Schweinfurt mission was "unofficially but expertly regarded as far from a setback on the daylight bombing campaign against Germany."
    The loss rate might have been 15 per cent if the force equaled the record 400 of last week end, compared with the average five per cent which is regarded as an "economical" rate of operation, and which both the RAF and Eighth Air Force have been maintaining or bettering.
    Acknowledging heavy damage at Schweinfurt, Berlin radio added the astounding claim that more than 174 bombers were shot down.
    It was the second USAAF heavy-bomber raid on Schweinfurt, which lies 65 miles east of Frankfurt. Taking part in the first "shuttle mission" to Africa, the Forts destroyed 147 German fighters on Aug. 17 and severely damaged all three roller-bearing plants. Thirty-six Fortresses were lost.
    Eyewitness reports reaching Stockholm last night said that ten ships were sunk in the Gdynia harbor by American Fortresses and Liberators in last Saturday's long-distance daylight raid. The Gestapo headquarters at Gdynia was demolished by a direct hit, it was reported.
    The damage to the coal docks, said the eyewitnesses, was so extensive that German coal shipments to Sweden and Finland will probably have to be suspended. The bombing was described as "very accurate."

    STOCKHOLM, Oct 17 (AP) -- German Secret Service gave German air defenses five hours' warning on the American Fortress attack against Schweinfurt Thursday, the newspaper Aftontidningen said today, quoting a report from a German underground radio station.