Lights on a tower crane shining through the fog.
>Lubas added that one helicopter had five soldiers aboard while the other had four, and they were using night-vision goggles NVG.
Wearing using NVGs restricts peripheral vision and causes problems with depth perception.
Looks like they were carrying out night formation flying and someone misjudged a manouver and got too close.
This sort of thing has happened before and will happen again no doubt.
Prayers for the families.
o7