Playboy model Katie May died from a simple visit to a chiropractor for an adjustment, which ultimately left her with a fatal tear to an artery in her neck ... according to the L.A. County Coroner.
TMZ obtained a copy of Katie's death certificate, and it clears up a huge mystery surrounding her sudden death in February. The document says she died when a blunt force injury tore her left vertebral artery, and cut off blood flow to her brain.
It also says the injury was sustained during a "neck manipulation by chiropractor." Her death is listed as accidental.
As TMZ first reported, Katie -- known as the "Queen of Snapchat" -- had taken a nasty fall during a photo shoot. She thought she had a pinched nerve and went to an L.A. chiropractor on Friday. She suffered a stroke on Monday, and remained on life support until Thursday.
Katie's family is aware of the coroner's findings. They would not comment on whether they or her estate would pursue legal action.