While driving up hill the engine began to lose power and then shut off

Now, I never had this problem before until just yesterday. I was going uphill when suddenly the car I feel started to struggle and lose power until it eventually turned off. I tried to power it on but all it does is crank and it just barely turns on and then completely turns off. The car has half tank and also we tried to jump starting it but also zero results. Please any ideas of what could be the problem?