Why is there a plate drop mechanism?

Tseng refers to an “Emergency Plate Release System”. I’m trying to picture the planning meeting that resulted in that one. What is it for? Seems like either you want to crush something below (monster infestation?), or you want to make a gap above (possible firebreak?). Given the release involves a fiery explosion, the firebreak explanation looks unlikely. Residual memory of Jenova? Did Midgar society feel a strong instinct to keep methods onhand to destroy a zombie horde, even if those didn’t quite make sense when given conscious thought?

(Related q: is it bad that there’s a forum I can ask this stuff? Wondering if it stops me writing it up as a fic. Otoh I have a buffer full of SCIENCE DEPARTMENT ANGST.)