If youre a Russian commander how do you seize a well fortified position, namely The Pit east of Mariupol?

1. Use a chemical weapon - like VX Gas from the 1996 Film The Rock - a nerve agent that destroys biology causing awful death.

2. Use a sedative like ketamin and try to put everybody to sleep

3. Conventional attack with helis, arty, armour and ground troops.

4 flame them out w fire

There are potentially thousands of innocents in the pit.

They are probably all already dead.

20 km of tunnels under the fort makes flanking easier.

You need proof of The Pit

Whats the best option? And Why?