Lead poisoning:

Robert Wayne Birch, a.k.a. Bob Birch, was found this morning by law enforcement officials with a gunshot wound to the head. At this time there is no evidence of foul play, and it is believed that Birch committed suicide.

Birch has played with Elton John since 1992, and was on many of his most familiar tracks, including Candle in the Wind from 1997. He has also played with a wide variety musicians from other genres, including Tina Turner, Eric Clapton, Cher, Sting, and Clint Black.
.
The Elton John website has issued the following statement in regard to the death of Birch:
.
“We are very sad to report the sudden death today of Bob Birch, Elton’s bass player and backing vocalist, in Los Angeles. Bob had been a member of the Elton John band since 1992, the longest-serving bassist in Elton’s touring band.
.
We send love and condolences to Michele Birch, and to their son, Jonathan.”
.

RIP Bob Birch...

RIP thoughts to the family