Smoke Plume After Initial Explosion

While driving with a friend 10 miles south of San Bruno, we saw a large explosion and then a tall smoke plume that had pulsating fireballs at its source. This was taken at 6:17pm. As the plume grew, I smelled burning materials and retreated further south to escape any possible chemicals that may be carried with it.The next photos were taken further south 35 minutes later from San Carlos and fire could still be seen at the base bursting up in a constant rhythm. People stopped on the side of the road to view it.