Smoke from underneath/gauges going crazy

Now I found out the first thing that happened was all of the gauges were flying all over the place. Eventually they all stopped working. At this point the car still felt perfectly fine except for the gauges not working. They were able to drive another five or ten minutes until while getting off the highway my son realized it wouldn't go more than about 5 mph. They got it to a gas station, shut it off and put dry gas in it (a friend who was with them thought maybe water got in the tank). They tried starting it but it was turning over but wouldn't start. They jumped it and it started. As they started driving they noticed they still couldn't go more than 5 mph and water vapor was coming out. They pulled over and shut it off. After that it wouldn't even turn over and trying to jump it did nothing. Any ideas would be appreciated.