Paramount began work on this movie before the real-life battle for Wake Island was over.
When the battle began there were 449 military personnel on the island and 1221 civilian workers. After the garrison surrendered, 52 military and 70 civilians had been killed. Japanese dead were estimated between 700-1000.
In real life most of the survivors were sent to Japanese prison camps, but 98 civilian construction workers were held on the island to help the Japanese with their defenses. After the Americans conducted a successful air raid in October 1943, the civilians were machine-gunned to death. A lone survivor escaped and later carved a message on a coral rock on the mass grave where they were hastily buried. He was later captured and beheaded. When the island fell in 1945, the Japanese commander responsible for the massacre was executed.
In a "History Channel" special, Wake Island: Alamo of the Pacific (2003), it claims that there were no survivors, when in fact there were.
The end of the movie shows the soldiers fighting to the bitter end, but in real life they surrendered after surviving the first wave of the Japanese attack.