As far as I can make out, a convey of rescue vehicles were requested taking a route adjacent to the runway.It was quite a few years ago now but when I worked air side at Heathrow if you needed to cross the runway you stopped at the stop sign and called the tower for permission to cross and even then we kept a good look out whilst crossing. We sometimes moan about H&S but it's there for a reason.
One of the videos shows the lead vehicle had turned 90 degrees side-on to the aircraft immediately before the collision:I read aviation reports on accidents and can explain.
The fire vehicles were on an exercise. The mock accident they were directed to was on a taxiway running parallel to the active runway, which was still under construction. The group of vehicles was approaching the taxiway and runway at right angles. The lead vehicle had been cleared to proceed up the taxiway which is short of the runway. Instead that vehicle missed the taxiway and thought the runway was the taxiway.
There is a lot of construction going on at the airport. It is not known whether the flashing red lights which normally guard an active runway were fitted here or whether they were operating. Nor whether the normal stop line markings on the taxiway were present or whether the lead crew just missed them.
The result was that the group turned onto the runway as the aircraft was taking off. The fire vehicles tried to steer off the runway, but one did not do so before being hit by the aircraft which had almost reached rotation speed. After the collision the crew abandoned the take-off and brought the aircraft to a halt before the end of the runway, I think to the side of the runway as it had sustained considerable damage including the loss of the starboard(?) main landing gear.
I quite agree but the lead vehicle made a 90 degree right turn as can be clearly seen on the video leaving the parallel running taxiway and crossing the runway directly. No doubt a thorough investigation will be undertaken. I do hope that the miraculously surviving fireman does in fact survive to put more light on this horrible event.That is what they intended to do, but along the parallel taxiway not the runway.