After struggling to think of how the parent of one of my charcters died, that wasn’t from cancer, a heart attack, or an automobile accident, I went into my two favorite author groups on Facebook (Alessandra Torre Inkers and Indie Author Support) and got some input from the members. Here are a list of ways to kill off a character that you may not have thought of!
Abdominal aortic aneurysm 
Accidental/freak gunshot
Advanced Auto-immune Disease
Affects of Alcoholism
AIDS/HIV
Alcohol poisoning
Allergic reaction/Anaphylaxis
ALS
Antibiotic-resistant bacterial infection
Arrythmia
Asphyxiation
Asthma attack
Avalanche
Bank robbery
BDSM play gone wrong
Blood clot
Blood pressure disorder
Boating accident
Bombing victim
Brain aneurysm
Brain infection post untreated sinusitis/tooth infection
Brain parasite
Bungee jumping accident – cord snapped
Buried when sand or dirt hole collapsed
Carbon dioxide poisoning
Carnival/amusement park ride accident
Caught in riptide
Celiac Disease
Choking
Complications from plastic surgery
Crushed by a fallen tree
Cyanide poisoning
Cystic fibrosis
Death by misadventure – freak accidents doing everyday things/extreme sports/taking a selfie
Deep-vein thrombosis
Diabetic ketoacidosis
Died saving others in a fire/shooting/natural disaster etc
Diving accident – pool, from a cliff, ocean
Drive-by shooting
Drowning
Drug overdose
During a sport game/practice – hit too hard or genetic heart defect
Eating disorder complications
Eclampsia
Ectopic pregnancy
Epidemic/plague
Epilepsy
Erotic asphyxiation
Extreme dieting
Fatal reaction to anesthesia
Fell down elevator shaft
Fell overboard from cruise/boat
Fell while hiking or rock climbing
Fire
Flesh eating virus
Flu
Food poisoning
Froze to death
Gangrenous gallbladder
Gas explosion
Given wrong medication by pharmacy/doctor/nurse
Haemophilia
“Hangman’s fracture” from a fall
Heart attack due to genetic heart abnormality
Hepatitis
Hit and run car accident
Hunting accident
Huntington’s Disease
Hydrocephalus
Hypertrophic cardiomyopathy – HOCM
Hypoplastic Left Heart Syndrome
Infection from unsafe abortion or unsanitary delivery
Infectious disease while working in 3rd world country
Infective Endocarditis
Injured during domestic violence incident
Injured in earthquake
Injured in tornado
Injuries received during boxing or MMA match
Job-related injury
Kicked by/fell from a horse
Kidney failure
Killed by bullet shot into the air by a careless person (idiot) celebrating a holiday (can be a mile or two away)
Killed doing parkour
Killed during carjacking
Killed during robbery – home, store, on street
Killer bees attack
Lacerated artery – carotid, brachial, femoral
Landmine or grenande from WWI, WWII, Korean War, Vietnam War
Liver failure
Lupus complications
Lyme Disease
Mauled by dog/lion/hippo/jackals/bear etc
Medication or blood type mixup in hospital
Meningococcal meningitis
Mining accident
Mistaken identity murder
MRSA (staph) infection after general surgery
Mudslide
Murdered by secret lover
Package bomb
Pancreatitis
Perforated bowel/colon
Perforated gastric ulcer
Peripartum cardiomyopathy
Peritonitis
Placental abruption
Placenta previa
Plane crash
Pneumonia
Postpartum hemorrhage
Pregnancy induced heart failure
Pulmonary embolism
Quicksand
Rhabdomyolysis
Ruptured aorta
Ruptured appendix
Russian roulette
School/mall/arena/club shooting
Scorpion sting
SCUBA diving – ran out of air, faulty equipment, stuck in underwater cave
Sepsis
Shark attack
Skiing accident
Skydiving/parasailing accident
Smoke inhalation
Snake bite
Snowmobile/ATV accident
Spider bit
Steriod use
Strangulation – intentional or accidental
Stroke
Stroke caused by birth control pills
Struck by lightening
Sudden Infant Death Syndrome
Surfing accident
Terrorist attack on unsuspecting public
Toxic Shock Syndrome
Train accident
Trichinellosis
Tsunami
Undiagnosed meningitis
Unintentional prescription or recreational drugs
Untreated head injury
Untreated rabies
Uterine rupture
War