Firm loses $2m to secretary

A local company is suing its secretary for theft amounting to $2 m.
Apparently the secretary had been depositing the company’s cash cheques
into her own pocket for a period of 7 to 8 years. And the cash cheques
were in sums of $30k to $400k.
 
Taking this as an example for discussion, who is to be blamed? The
secretary is at fault for sure. What about the company? How could a
secretary keep