Gas pedal locked up?
Two possibilities, -- one is that the "throttle cable" - which is several strands of wire has "shredded out" inside the cable shield, and jammed!
The other is that you don't have good ground from engine (or minus of battery) to frame. And cable was good enough ground (that power was flowing through it to ground), -- however if current gets high enough (and possibly several strands of cable broken alredy),- you had enough curent flow to heat the cable up "cherry red" and melt into the shield and now it will not move!
Since electricity (power + amps) will flow through the easiest path,--- and if body not grounded to battery -- it will not have normal "provided path" available -- so it will find another!
Even if the cable is broken --the remedy is the same, -- put in new throttle cable! Just make sure and check grounding (to make sure it is not that ), so it won't happen again!