First failed rent payment from tenant. Now what?

[Matthew Wyn]

I officially have my first "failed" rent payment from a tenant.

I use an online payment system where tenant's automatically pay rent and have verified their bank accounts through that site.

I've had this tenant/roommate a few months now.

This tenant's rent payment was processing via ACH transfer on the payment site a few days, then the payment failed.

I'm really floored. I've never had a tenant not pay, let alone have a failed payment.

What would you do if you were me? Get a lawyer to start eviction asap? I'm lucky in that it's a roommate situation so things should be easier. I'm also just floored that this tenant/roommate has paid before, has never had any evictions/bad rental history, is helpful, etc. then has a failed payment. 

I'm hoping this tenant's bank screwed up and not that the tenant had insufficient funds, but I'm not hopeful.