prius was left running when came back off and won't start.

I was clearing my driveway of snow I mover my 2010 prius and finished the driveway. When I came back to move the car back it was off and I can't get it started the exclamation symbol light was on I can't lock the doors or anything. Any Ideas it is 12 years old with over 500k on it do I just take it out and shoot it?

 

Lots of gas I just filled it. I'll check the battery.

 

So if it is the battery what would cause the car to die while running? For most cars it would be the alternator do you think that is the case here? I don't want to sink a whole lot of money into it at this point.

 

Left running as in it was idling engine running

 

Any ideas why it would die then? I don't want to spend upwards of $350.00cnd to find out it's something else.

 

Yes, it was in park. No, I did not shut it off. I'll try jumping it this evening. If not the 12v battery what else could have caused this?

 

I have had to do the bearings twice, did the head gasket 2 years ago that is the reason I hate going to dealers for service. Regular oil changes. As for driving, I was working in sales did a lot of 10-15 km trips each day, not a lot of highway driving it is just a good car. I just wish I could understand how it works I have a 76 spitfire that I brought back from the dead but most of the Prius like most new cars you need a degree in computers, not mechanics.
Hope to get out this weekend to work on the Prius not hopeful it's just the 12v battery though it sounds like if it was bad it wouldn't cause the car to die while running.