Phaëton wished to show his siters Prote and Clymene what a fine fellow he was: and his fond mother Rhode (whose name is uncertain because she had been called by both her daugheters' names and by that of Rhode) encouraged him.

But, not being strong enough to check the career of the white horses, which his sisters had yoked for him, Phaëton  drove them first so high above the earth that everyone shivered, and then so near the earth that he scorched the fields.

Zeus, in a fit of rage, killed him with a thunderbolt, and he fell into the river Po. His grieving sisters were changed into poplar-trees on its banks, which weep amber tears; or, som say, into alder-trees."

(Graves)