I am so sorry to hear that this happened to your employee, and I am glad she wasn't hurt. While you can't control the environment away from your work site, you can train employees who travel for work or who work outside your office how to protect themselves from violent crime. You may decide that when dropping off materials outside of business hours, two employees will go together. Or, maybe it is more cost-effective and protective of your employees to ship materials if that's possible.

Even in low-crime areas, there is a greater chance of being a victim of a crime during hours when others are not around, such as late at night or early in the morning. Avoiding these times, or asking someone to meet your employee at the drop off site can make it less likely a crime will occur. The National Crime Prevention Council has a good list of tips for all of us to follow to reduce the risk of becoming a victim of a crime. Adapting this list and sharing it with everyone who travels or works away from your company's locations, as well as all of your other employees, is a great way to equip them to be safe at work and at home. 

Best wishes!

I would definitely have two people when doing off site deliveries or ship the items.  Sorry this happened to your employee and team.