[yesthatjallen]

There appear to be a couple quick flashes at the beginning of the video.

[donozark]

Power lines perhaps? Causing the flashing at beginning of video? Hard to see...

[jughandle]

Some of the span is already gone at that point, electric wires/transformer?

[PapaBear3625]

There appear to be a couple quick flashes at the beginning of the video.

Yep. Doesn't look like a normal structural failure.

[Mark17]

There appear to be a couple quick flashes at the beginning of the video.

I saw them too. I will believe it was a terrorist attack, until it can be proven otherwise. If the government says it was not a terrorist attack, then I believe it was a terrorist attack.

[OregonRancher]

Definitely. Two bright flashes coming from the base of the bridge support, most likely terrorism.

[CaptainK]

I looked at the video from points 18:40-18:44 and slow motioned it. There does appear to be a flash. If you slow mo it as you watch it appears more pronounced.

[21twelve]

I can’t imagine why the entire tower at the base would fail like that from design, corrosion, etc. I was thinking what if a train derailed and hit it? I haven’t watched the video.

And once the base of the tower by the little building went, it dragged the two upper parts of the two towers farther away.

Wow.

[cynwoody]

There appear to be a couple quick flashes at the beginning of the video.

Example of a deliberate demolition, viewed from two angles:

https://www.youtube.com/watch?v=AiK5vurY9ZQ