This CDC site https://wisqars.cdc.gov/data/lcd/home says for the year 2020, the leading causes of death for those below age 45: (a) for Whites, it is unintentional injury which includes overdoses and car accidents (b)for Blacks, it is also unintentional injury but homicide is significant (c) for Asian Pacific Islanders, it is unintentional injury, suicide, cancer, and congenital abnormalities.