I have tried to find a few more answers to how this happened but have not found much. I did hear that the tap section at the top of the riser had some "field engineering" modifications. I don't know exactly what was modified but I would assume it didn't help.
George, oddly enough this seems to be the opposite of what you have seen, it was field modification that seems to have failed. Now I don't want to say that it was the actual modification that was the cause of this failure, especially because numerous factory 90's blew out, but the field mod did not stand up to the fault. And yes to a few things you asked. This is an aluminum bus and also pretty close to K street. The building is on N. Fairfax Dr. in Ballston.
mxslick, I truly do not know the cause of the fault. I do know that the final line in protection for the building opened and it was closed without troubleshooting the fault. What has been said is that water caused the fault but I don't know. Seems like a huge fault to blame on water alone.
Pete
