In the Equal House Chart, he had (the drowning death), Atropos Transiting his 8th house.,of death.
Saturn also (over the 8th - Equal houses), is transiting at 17°Aries.,that fateful night.
We see that over his 6th house of Health Uranus (the unexpected event) over his Natal Moon at 8AQU.
Transiting Pluto at 4SAG rx, over his Natal Atropos, (the asteroid we use for death, along with Moira, the 4 fates) Atropos means, "Cutting the Ties that bind us".
Pluto is the indicator of the death near his home...Uranus the way he died, (by accident)over the health house.; along with Neptune (the drowning event - at a very critical 29th deg.45minutes Capricorn;
and Saturn of course, always around 'the lord of karma" house 8.
This natal pretty much fills the requirements of a death chart's transits.
Moira (one of the Greek Fates), is transiting over his 1st house as is the BML.
He had been pretty depressed, (see his photo), and biography, it seems to me, most of his young life and told his girlfirend, he found out it was Bi-Polar disorder.
The Natal gives us only an inkling that there could be trouble, (Saturn in Pisces 22nd degree rx; in the chart - so "repeating" the karmic cycle
Chiron nearing the 22nd degree, his Vertex 0CAP. we wouldn't know about,.....it must have meant a person, or a lover (5th hs.)
These very late degrees such as Scorpio Sun 25th deg.,Venus in Scorpio, 28th deg.,are all worrisome for great depression , alcholism, and/or drugs as well.
His Mars in the "loss degree" at 21Virgo
interesting death chart. I'm sure his life however was quite missed by many (see the many credits of accomplishments to his name on the biog.)