Maybe it's my cautious nature, but I don't believe a first date is a sure thing until I see the other person standing at the bar waiting for me. And it is in cases like this that makes me feel good about my defensive pessimism.
You didn't (and still don't) know much about this guy, so a hundred different things may have suddenly interfered with his availability and interest level. Did he get back together with an ex in the past few days? Did he get swamped at work? Did he just decide that he wasn't into you anymore and decide to just cut off communication now? In that magic time before the first date, you don't owe him anything and he doesn't owe you anything. You're still, effectively, strangers. And strangers sometimes are inconsiderate to other strangers.
There is, of course, a chance that a text will come in at any moment that reads "Sorry, was super busy, can't wait for our date." But for sake of your own sanity, I suggest you move on as if that's not going to happen. Be pleasantly surprised if it does, but chalk it up to the unkindness of strangers if it doesn't.