Why has my car stopped? 93 geo prism?

for the last few weeks my oil light has be flickering off and on so today on the high way with my son god son and another child was in the car i was going 64 mph down the high way every time i pressed the gas it got louder so i slowed down to get on the exit and as soon as i pressed the break i heard a huge pop sound the inside of the car filled up with smoke so i pulled to the side of the highway and lift the hood and there was smoke and a small flame (got all kids out of the car) then there was a hole under neath the engine that had out pouring out of it also the flame that was seen came from that hole .. there is now gaS over everything i just got a oil change 3-4 weeks ago