The 6th and 9th Bombardment Groups joined in the attack on Tokyo on 25 February, as did the 314th Bombardment Wing's 19th Bombardment Group, flying out of North Field, Guam. With these new tactics, a total of 302 B-29s participated in the "Operation Meetinghouse" raid on Tokyo on the night of 9–10 March, with 279 arriving over the target. The raid was led by special pathfinder crews who marked central aiming points. It lasted for two hours. The raid was a success beyond General LeMay's wildest expectations. The individual fires caused by the bombs joined to create a general conflagration, which would have been classified as a firestorm but for prevailing winds gusting at . When it was over, sixteen square miles of the center of Tokyo had gone up in flames and nearly 100,000 people had been killed. Fourteen B-29s were lost. The B-29 was finally beginning to have an effect.