Had 4 prepaid packages outgoing first class USPS on my porch and they were stolen. What can I do?

I send out about 2 packages a day through USPS's prepaid shipping service and haven't had any problems in the years I've been doing this.

I had my packages in the lobby of my apartment complex and the tracking info hasn't been updated, even though they've spent a few days in transit.

I fear that the packages were stolen from lobby, since no information has been received by USPS for accepting these packages.

The value of the packages ranges from $10.00 for 3 of them and $100.00 for 1 of them.

I didn't purchase any insurance, as I've never had any problems in the 1,000+ times I have done this.

Am I out of luck, or is there any way I can get my money back from these items?