[Magic] Earth to Air in a stone tower

[wmervine4]

This past weekend I ran another session of my home brew fantasy campaign (inspired by and including material from DF and ToG 3e). During a battle in a stone tower, the timely use of the Earth to Air spell (standard Magic) has left me with some questions about the consequences of this action.

For a slight bit of background, the adventurers are currently in an old one-story fort that is mostly rectangular in shape, but features a three story tower in one corner. The fort is constructed entirely of gray stone and is built with quality masonry that has survived for several centuries.

Before entering the tower, the group employed Sense Life to detect that there were 9 adversaries inside. They all went in and one of the group charged up the ladder to the second floor encountering 8 foes waiting for her (the 9th is presently unaccounted for). For a time during the rest of the battle, there was some concern about how to get the rest of the party up to the second floor to assist her. Several people used the ladder which took a few seconds, but one guy had a different idea. Rather than waiting his turn to ascend the ladder, the martial artist/ritual air mage of the group decided to use Earth to Air to punch a hole in the ceiling (the floor for those on the second story).

This is where I'm wondering what could/should "realistically" happen. The tower is 30' (10 yards) in diameter with thick stone walls and stone floors. The only natural opening in the floor on each level is a 3' x 3' square against the wall where an iron ladder is attached leading up to the next floor. This new opening is on the floor of the second floor (ceiling of the first floor) one hex (3') away towards the center of the room from the natural opening for the ladder that leads up from the first floor to the second. Stated another way, there is an open hex against the wall where the ladder comes up, then moving towards the center of the room, there is a hex of stone floor that is still intact, and then the open hex that was Earth to Aired.

We were substantially over our allotted time for the game, so I ended the session at the end of the battle during which the spell was cast, so a few seconds have passed since the actual casting. Using some rough math, I figure the 8 adversaries on the second floor and 5 PCs/NPCs with all their equipment total about 3,500 lbs.

My main question is, would this use of Earth to Air compromise the structural integrity of the tower causing a collapse? If so, how long would this take? Seconds? Minutes? Would there be a way to avert this disaster?

I recognize that from a story perspective I could just hand wave this issue entirely and let the group move on as though nothing had happened, but I would like to impose even a smidgen of a reality check on this scenario rather than blatantly ignoring something that seems to me like a potential catastrophe.