How did Hippolytus die?
Also question is, what is the fate of Hippolytus?
Hippolytus' superhuman resistance to the force of desire, just like Prometheus' transgression, causes the gods to take notice. Desire itself is the law or fate of human life, and the audience watches it destroy Phaidra from within before seeing Hippolytus killed for his arrogant rejection of it.
Herein, how did Phaedra die?
Theseus cursed his son; so, a bit later, Hippolytus' chariot horses were scared by a sea monster and dragged him to death. In another version, Phaedra lied to Theseus, who killed Hippolytus; out of guilt, Phaedra committed suicide.
In Euripides' tragedy Hippolytus, he was son of Theseus, king of Athens, and the Amazon Hippolyte. Theseus' queen, Phaedra, fell in love with Hippolytus. When Phaedra's passion was revealed to him, he reacted with such revulsion that she killed herself, leaving a note accusing Hippolytus of having tried to rape her.