Here is a great link that gives a lot of information on removing dead trees. A dead tree had cause bodily damage to anyone near a dead tree if it falls.
A dead dry tree is also fuel for fires.
https://bss.lacity.org/UrbanForestry/StreetTree/RemovalPermit.htm
LACPP.com is a property preservation company that can safely remove a dead tree in the City of Los Angeles.