[R_Kangel]

"Almost looks like a gas main."

I am hearing it originated inside the building which would be consistent with a gas line failure. The timing however coupled with a double explosion is quite suspect. Does anybody know if there is any parking structure/lot in the area?

[redgolum]

Not sure. Never been to that area.

My comment was the large fireball. In a previous job, we worked with flammable gas a lot. Large balls of fire are a gas burn. Explosives typically don’t have that much “Hollywood”.

At this point, it doesn’t matter, praying for the victims

[cuban leaf]

A gas main break and double explosion right at the Boston marathon finish line? What an AMAZING coincidence. ;-)

[rlmorel]

There is a hi rise parking lot in the area. I watched the race from there once, but I don’t know how close it is to the finish line, but it is close.