NAHA, Okinawa — After the shocking news of President Kennedy's assassination swept Okinawa Saturday, people on the island began asking each other in anguish: "Why did the assassin have to kill. the young President?"

"I am still wondering why the assassin had to kill. Wins it necessary for him to kill the President?" said Yoneko Hanashiro, 20, a Ryukyu University student.

"I first associated the killing with the Cuban problem when I first heard the news, but I just couldn't believe such a thing really happened," she added.

"How can Mrs. Kennedy survive such sorrow?"

Early Sunday morning bus passengers on Okinawa devoured local newspapers that carried photographs of Kennedy and stories of the assassination. Words most used in their conversations included, "terrible." "cruel," "young." and "crazy."

News of the assassination also touched people in remote northern Okinawa villages Saturday. In Nago, people flocked around bulletins posted in front of news bureaus of local newspapers and shook their heads in disbelief and anguish.

In deference to the President's death the Japanese flags over the government buildings, originally raised full-mast to celebrate the annual Labor Thanksgiving holiday Saturday for the Ryukyuans, were lowered to half-staff when the news of the assassination reached here.

Japanese flags at other local public offices, at ports and schools were also lowered or removed entirely. In Kadena, villagers cut short their two-day festival for Sokan Noguni, who introduced sweet potatoes here in the 17th Century.

In Koza, all "A" sign bars were closed Saturday night after Yonezo Seda, chairman of the "A" Sign Bar Owners Assn, issued a message to the members of the association.

Thousands of Okinawans flocked to their television sets Saturday and Sunday to watch local telecasts on the President's life and death.