The melting point of marble is 800ºC and if reports are true that it's a construction mistake and not something more drastic it stands a good chance of not collapsing.
You can cause a drinking glass (melting point 1400C) to explode if you expose it to 100C and 0C water in quick succession. Differential heating, moisture vaporizing, and expansion/contraction are larger concerns than the stone becoming lava.
