Orion, whilst swimming to escape a giant scorpion (again sent by Apollo) is killed by Artemis' arrows after the goddess could only see his distant bobbing head and failed to recognise the hunter. This tragedy was after the two great hunters had been sporting around Crete together.

What happened between Artemis and Orion?

Artemis and Orion passed the summer together. By day they hunted and sported, challenging each other to foot races, archery, and storytelling. In the evenings around the fire they bared their souls and told each other about their lives, their lost loves, their secrets.

Why did Apollo trick Artemis into killing Orion?

Knowing well his sister's skill with the bow, he cunningly expressed a doubt that she could hit the distant black spot with an arrow. Artemis accepted the challenge and thus killed Orion.