10.2 - Transport or Garrison Destroyed

If a Transport that is a Vehicle or a Garrison (Fortification that can have embarked troops) is Slain, Wrecked or Explodes, then any models embarked must be placed within 3" of the destroyed model (or its former location). This is called an Emergency Disembarkation. The Explosion or Wrecked result is resolved and then you must roll a Dice for each model that disembarks. For each result of a 1, one model that disembarked from the destroyed Transport is slain and removed from play (see 1.2.2).

If there is no room to place any models when making an Emergency Disembarkation those models that cannot be placed are slain and removed from play.