Helicopter seen in background of this pre-collapse footage. The audio is from the post-collapse response to two primary events:

On King, between 6th and 7th Steets, a truck/van had a mural painted on it’s side with a plane flying into NYC. Two people were inside - they got out and ran, and were apprehended. According to what we hear on this tape, the van ‘exploded’. I cannot confirm this. If you have any kind of PRIMARY SOURCE news coverage on this, please forward it to me. Thank you.

Note that after this van is discovered, a relocation of mobilization point for all units is requested at Trinity and Liberty. Perhaps this is why we never hear of the incident again - the ‘damage control’ team was sent in.

At Cedar and Trinity, the subbasement explosions from the WTC apparently caved in a subway tunnel. This is unconfirmed, and is not the focus of this portion of the firefighter tapes.