The 'Doolittle' raids take place today: American bombers launch attacks on targets in Tokyo, Yokohama, Kobe and other major Japanese cities. Although not of great military significance, they are valuable for propaganda and morale-raising purposes, as they are the first time that the main islands of Japan have been hit.
News of the raids seems to have taken a few days to reach the internees. On April 22 R. E. Jones records 'Japan bombed?' and the next day he makes an inaccurate note of the damage done.
American missionary John Bechtel was later to claim that the Japanese-sponsored Hong Kong News was not delivered in Camp, or not produced at all, on this day because of the raids. The American bombers arrived over Tokyo at about noon Japanese time so it's possible that it was April 19 that the paper didn't arrive.
Source:
Bechtel: John Bechtel, Fetters Fall, 1945, 220