Hello, I'm Jason. I will do my best to answer your question quickly and accurately using the information you have provided.
Ok, so driving normally into work, the car was fine.
Then you tried to start it after work, did the engine spin over?
Ok, but you did find the single small wire connector not connected to the alternator?
and the alternator connector? It was just hanging there?
very odd. I've never seen one just fall off without prior work
however, let's move on...
The most common cause of a no-spark condition in these cars is a faulty crankshaft position sensor
this sensor is bolted to the engine, near the transmission bellhousing, just behind the oil filter
no connection between the small wire and the alternator? The alternator simply wouldn't charge
in any answer that I give through this format, on cars that I have not personally diagnosed, nothing is 100%. However, if the battery is showing at least 13.6v with the car running, the alternator is not the issue
Ok, got it. The crank sensor sends what we'll call a pulse in the form of a wave (it's more involved than this) to the engine management computer. This pulse is the only way the computer knows when cylinder #1 is at top dead center, and the only way that the computer will be able to pulse grounds to the coil to fire the spark plugs
I seriously doubt it's the coil (there is one central coil), and again, if I saw this condition, I would replace the crank sensor, as a result of my experience working on literally hundreds of these cars
4 on a scale of 1-10, 10 being most difficult. The wire lead from the sensor travels a bit of a distance, so it's just time consuming. Figure about 2 hours for a novice. Also, removing the oil filter helps access
So hopefully this has sufficiently covered the original question
Respectfully, we're working through a format designed to give well-researched answers given by experts very familiar with your particular car. Unfortunately, we cannot go through complex diagnostic paths here due to lack of scan equipment, tooling, mechanical knowledge, and other barriers. I am strongly suggesting that you replace or have your crankshaft position sensor replaced. Your only other option is to have the engine control module scanned for codes to see if there is anything else stored. However, often, failed crank sensors do not throw codes.