Dear friend,
You have given complete information as to what exactly happened. Have you presumed the "negligence" of the employee?
I recommend you ordering the enquiry. Focus of your enquiry should be on the incident and not on the person. The Enquiry Officer (EO) should check whether the SOP was well in place. If your company delivers the "expensive" goods, then you supposed to have the SOP.
If not SOP then EO should find out whether any specific instructions were given to the employee on the precautions that he should observe while accompanying the goods.
If you do not have SOPs, if the instructions were not given in writing, then you do not have the right to blame the employee. It is the failure at the managerial level. You can hold the junior employee responsible provided there is non-compliance of the orders or instructions.
Yes, notwithstanding the SOPs or written instructions, one is expected to use common sense. But even then also, employee cannot be fined more that 5-10% of his salary for the negligence.
Thanks,
Dinesh Divekar