Radio Reports Japan's Attack on Pearl Harbor
aFor most Americans, news of the Japanese attack on Pearl Harbor came as an interruption to their favorite radio programs on an otherwise tranquil Sunday afternoon on December 7th, 1941. An Associated Press bulletin at 2:22 PM Eastern Standard Time first reported the attack to mainland news organizations and radio networks. After confirming the initial bulletin with the government, the major radio networks interrupted regular programming beginning at 2:30 PM, bringing news of the attack which was still in progress,

In  New York City,  station WOR broke into the local broadcast of the Giants and Dodgers game while CBS informed listeners of the attack at 2:25 PM EST.  NBC broadcast their first bulletin nearly 4 minutes later at 2:29:50 PM . Within minutes the CBS radio network broke into normal programming with more information read by announcer John Daly. 

Honolulu NBC radio affiliate KGU, provided the first and most comprehensive radio coverage of the event. What was not known at the time was that Japanese planes, still swarming overhead in Honolulu, had used the station's signal to guide their planes to Hawaii.

While the attack was still in progress a reporter for KGU radio climbed to the roof of the Advertiser Building in downtown Honolulu with microphone in hand and called the NBC Blue Network on the phone with the first eyewitness account of the attack,  "This battle has been going on for nearly three hours... It's no joke, it's a real war" said the reporter.     Ironically, a Honolulu telephone operator interrupted the broadcast after 2 minutes declaring a need for the line for an emergency call.

The attack on Pearl Harbor  was an unannounced military strike conducted by the Japanese navy against the United States naval base at Pearl Harbor, Hawaii on the morning of December 7, 1941. It resulted in the United States' entry into World War II. The attack was intended as a preventive action in order to keep the U.S. Pacific Fleet from influencing the war that the Empire of Japan was planning in Southeast Asia against Britain and the Netherlands, as well as the U.S. in the Philippines. The attack consisted of two aerial attack waves totaling 353 aircraft, launched from six Japanese aircraft carriers.

The attack sank four U.S. Navy battleships (two of which were raised and returned to service later in the war) and damaged four more. The Japanese also sank or damaged three cruisers, three destroyers, and one minelayer, destroyed 188 aircraft, and killed 2,402 and wounded 1,282.  Japanese losses were minimal, with 29 aircraft and five midget submarines lost, and 65 servicemen killed or wounded. One Japanese sailor was captured.

President Franklin D. Roosevelt had earlier moved the Pacific Fleet to Hawaii and ordered a military buildup in the Philippines in the hope of discouraging Japanese aggression in the Far East.   The transfer of the U.S. Pacific Fleet from its previous base in San Diego to Pearl Harbor was seen by the Japanese military as the U.S. readying itself for a potential conflict between the two countries.

Preliminary planning for an attack began in early 1941, under the auspices of Admiral Isoroku Yamamoto, then commanding Japan's Combined Fleet.  Full-scale planning was underway by early spring 1941, primarily by Captain Minoru Genda.

Over the next several months, pilots trained, equipment was adapted, and intelligence collected. Despite these preparations, actual approval of the attack plan was not issued by Emperor Hirohito until November 5, 1941. Final authorization was not given by the emperor until December 1, 1941. 

By late 1941 U.S. Pacific bases and facilities had been placed on alert on multiple occasions, with hostilities between the U.S. and Japan expected by many observers.  However, U.S. officials doubted Pearl Harbor would be the first target in any war with Japan, instead expecting the Philippines to be attacked first due to the threat it posed to sea lanes to the south and the erroneous belief that Japan was not capable of mounting more than one major naval operation at a time.

President Franklin D. Roosevelt to proclaim "December 7th, 1941 a date which will live in infamy".

President Franklin Delano Roosevelt address to Congress and signs the Declaration of War on December 8, 1941
NBC Radio News bulletin of the attack broadcast at 2:29:50 EST Dec. 7, 1941.
WCBS New York broadcast their first report of the attack at 2:25 PM EST as read by newsman John Daly.
USS Arizona sinking during the attack.
December 7, 1941
Honolulu radio station KGU first reports the attack via phone to NBC in New York. With Japanese planes still swarming overhead, a reporter climbed to the roof of the Advertiser Building in downtown Honolulu with microphone in hand and broadcast, over the NBC Blue Network from KGU, the first eyewitness account of the attack, reporting "This battle has been going on for nearly three hours... It's no joke, it's a real war." Ironically, a Honolulu telephone operator interrupted the broadcast after 2 minutes and ended the transmission for "an emergency call."

Unforgettable Moments in Radio History

1925: Calvin Coolidge is the first president to be inaugurated live on radio.
1937: the Hindenburg crash is covered by live broadcast.
1938: Orson Welles' "Mercury Theater of the Air" presents a reading of the "War of the Worlds" so realistic, thousands of people actually thought Martians were attacking.
1941: The Japanese attack on Pearl Harbor is broadcast live by a Honolulu KGU reporter who phones a station in New York City that broadcast his call to the nation.
Later in the evening, Hawaiian time, KGU broadcast this brief summary of events and eyewitness reports.
Before 7 am, the radar station at Opana Point picked up a signal indicating a large flight of Planes approaching from the north. These were thought to be either aircraft flying in from the carrier USS Enterprise or an anticipated flight of B-17s from the mainland, so no action was taken.

The first wave of Japanese aircraft arrived over their target areas shortly before 7:55 am. Their leader, Commander Mitsuo Fuchida, sent the coded messages "To, To, To" and "Tora, Tora, Tora," telling the fleet that the attack had begun and that complete surprise had been achieved.