Abinadi is executed with fire. While this invokes images of being burned at the stake, that does not appear to be the means employed. Key to understanding what is happening is that he was “scourged … with faggots, yea, even unto death.” Faggots are bundles sticks that are set on fire. Scourging is to strike against the flesh. This is a terrible means of torture that was unfortunately widespread through Central and even North American indigenous tribes.
A bound captive would be beaten with or jabbed with the burning bundle, burning the skin, but not causing death. It was a process that could be extended for a long time and was more brutal than burning at the stake. In some cultures, when the victim passed out from the pain, the victim was allowed to rest and recover consciousness, and was then tortured again.
With such a terrible death, it is even less surprising that Abinadi would curse Noah with the same death. In Alma 25:9–11, Mormon writes that this prophecy was even visited upon the seed of the priests.