Ultimately, high command approved the application to deploy a tactical nuclear weapon, planning to launch a tactical nuclear missile into the tunnels appearing on Hong Lake, then use the nuclear explosion to destroy all tunnels in the entire lake area.
According to calculations, the shockwave from the nuclear explosion will destroy most of the channels at the bottom of the lake, and the inflow of the melted lake water, after cooling, will thoroughly seal off any channels that might still exist, enough to block the threat from beneath Hong Lake in the short term.
If the alien creatures want to invade again, they would have to hollow out the subsurface of Hong Lake once more.
