Tenant's front door was broken during a break in.

[Andrew P.]

We have a tenant (in Austin) that had their front door broken while they were gone during a break in.  They do not have renters insurance, which is our fault for not requiring it.  

(Devils Advocate) If I was to guess, it was probably the tenant who lost their keys, or someone they knew.  Regardless, is the tenant or the landlord responsible?  

We've never run in to any issue like this, so thank you for your help.