In Norse mythology's Ragnarok, which two gods kill each other in combat?

In Norse mythology’s Ragnarok, Heimdall and Loki kill each other in combat.

Heimdall is the vigilant guardian of the gods’ stronghold, often associated with the rainbow bridge Bifröst. He possesses extraordinary sight and hearing and blows the horn Gjallarhorn to announce the beginning of Ragnarok.

Loki, a trickster and shape-shifter, becomes an enemy of the gods after a series of conflicts, including his role in Baldr’s death. At Ragnarok, he fights Heimdall, and the two kill each other. Their mutual destruction reflects a long-standing opposition between the guardian of the gods and their former ally turned adversary.

Some modern retellings alter the participants or emphasize different battles, but the surviving Norse accounts specifically pair Heimdall and Loki in this fatal duel. Gjallarhorn’s warning and the duel are separate details within the same apocalyptic sequence.