There were three B29s sent out early on weather flights that day. "Straight Flush" went to Hiroshima while "Jabbitt III" went to check Kokura and "Full House" went to Nagasaki. Those last two were the secondary targets.
Once the word came back from "Straight Flush" that the weather at Hiroshima was good, Paul Tibbetts and the crew of "Enola Gay" took off followed by two other B29s, one loaded with cameras and one with instruments for recording blast readings.
They were 15 miles from Enola Gay when she dropped.
The Japanese were used to single B29s flying over Japan on Weather recon and tended not to intercept them.
There had been an air raid alert earlier that day at Hiroshima, but this was a reaction to the earlier single weather B29 flight.
5 hours after the strike another B29 was over Hiroshima taking pictures for damage assessment.
No escort fighters along on any of those flights and no other B29 raids that I can find from my sources.
Dan/Slack
