XXXTentacion was shot in the neck during an alleged robbery ... and, according to one person on the scene, it appeared he died instantly.
TMZ broke the story, XXX was murdered Monday in South Florida when two armed men approached his car and shot the rapper. An eyewitness tells us a bullet struck XXX in the neck -- and he went immediately limp -- losing all signs of life, including pulse.
The police dispatch also revealed just how dire XXX's situation was ... classifying him as a level 1 trauma patient and describing his state as "comatose." The eyewitness says it was clear to him ... XXX had passed.
The dispatch revealed the alleged shooters made off in a black Dodge Journey.
A statement from the Broward County Sheriff's Office classified the incident as a likely robbery -- XXX's Louis Vuitton bag was stolen -- but, so far, no one has been arrested.