Car dies, now won't restart

[Danny]

Hi all, the patient is a 2001 A4 1.8t. Just got back from hiking by the Delaware water gap (about 2 hours roundtrip) from where I live. Car drove fine, even stopped at two stores before I got home. Got back in the car and within a block lost power, car conked out and now won't start. There's about a half tank of gas in and I replaced the spark plugs about a week ago. A couple of days ago the car hesitated briefly, similar to when the ignition coils throw a code and the check engine light even blinked briefly. I spliced new ic connectors a while ago and they've been fine. The only code I have is for an O2 sensor which I just haven't gotten around to change.Gonna let it cool down before I push it home. Any ideas  ? 
Tia
Danny