The source of the explosion is easy to identify by comparing it to these two videos[1][2]. You can see that a crescent-shaped area of the pier gets obliterated creating a water-filled crater in front of the silo (the building with 16 tall cylinders in a row). What's fascinating is that the flat buildings on the other side of the silo are obliterated as well. From the two videos below, it looks like the shockwave wraps around the silo and destroys stuff on the far side.