I'm looking at the time of the tragedy stated at https://www.insider.com/southern-califo ... say-2019-9
It occurred at 3:30 am day of Sun hour of Mars. With Mars and Sun being conjunct exactly at 9°41' Virgo. With Mercury quite close, probably some sort of technical hindrance. Old Greeks stated that Mars be malicious and Sun mixed (good with good planets, bad with bad).
Also if you look up Exorcism of Emily Rose film, they stated 3:00 am being the dead of the night, the most vicious time of the day. Observing this quite a while I agree, though not sure if the time lasts one full hour or less.
Given these circumstances the result seem like a work of evil spirits, therefore a tragedy to us.
I'm so sorry for this happening.
Also, didn't have the heart to tell you, but I can see some transference or sympathetic (not sure about the terms) magic going on there.
California was said to be mostly hot and sunny, ie of element fire.
Southern part is often associated with fire.
You took ashes of a burned man on that boat. I have a gut resistance to the idea of cremation. I can see some spirits of the departed attached to their graves at cemetery, it was a still usable dna that was burned at cremation, perhaps the spirits get to feel their bodies being burned that way and don't like it. Perhaps traces of his ash were attached to a boat and spirit didn't like it.
Moreover you being a witch might have some befriended spirits of witches burned at stake hanging around you.
Or whoever malicious capable of doing the magical combination to make that thing happen might have seen the opportunity in the astral.
Or perhaps the burning was in the air for some other cause with two subsequent events just pointing it out.
This way occult can help prevent the disasters. Hebrew lore offers to call Seheiah to ward off perils by fire.
Aub and Vevaphel to protect from perils by water.
Hugs and hope you can let it go. The blame-game is always for nought.