The smoke and date clues leads to some interesting history. I expect the photos were taken on the next morning.
Smoke is from two burning aircraft.
The base would see extensive activity throughout the second half of 1967, culminating in the Battle of Dak To in November 1967. On the night of 15 November, North Vietnamese mortar fire hit two C-130 transport aircraft (#62-1865 and #63-7827) destroying them and setting off secondary explosions and fires in the ammunition dump and fuel storage areas
From
https://infogalactic.com/info/%C4%90...3%B4_Base_Camp