Almost every fuckn bread. The explosion was on the left side, in front of the ATT building. The fireball on the left side is immediately shrouded in smoke and debris. The fire on the far side of the street then itself gets smothered by smoke and rubble because it's on the other side of the street.
It's pretty obvious when you watch the higher quality video.
Whether it was the RV that exploded or something very close to it is largely irrelevant to the questions of who and why did they target the ATT building.