How do I destroy the napalm tank?

I'm doing the Napalm Production Site mission, but can't get through even the very first area, because the tank won't explode no matter how much I shoot it.

As far as I know, the tanks are supposed to blow up when you shoot the red box on them. Yet they don't. I've tried using different guns, grenades, restarting the mission, restarting the game, all with same result.

Solution 1:

You need to shoot the red "box" in front of the tank.

Solution 2:

It's a bug of some sort. A few of the tanks valves won't take damage, so you apparently need to restart the mission.

I tried fast-traveling to fix it, but it appears you need to reset the mission.

Solution 3:

I had the same problem. I left the mission and did another mission before returning to this one, i.e. restarted the mission.

Then, I shot the tank out first, and then the cleaners, and it worked. The first time I took out the cleaners first and couldn't take out the tanks afterwards.

Maybe this helps. Good luck!