(27)Only in the case of an external event beyond the control of the depositary, the consequences of which are unavoidable despite all reasonable efforts to the contrary, may the depositary avoid to be held liable under Article 24 of Directive 2009/65/EC. The cumulative fulfilment of those conditions should be proven by the depositary in order for it to be discharged of liability, and a procedure should be laid down to be followed for that purpose.