How did Bruce Lee truly die?

Okay I know I’m on a role with death questions. But I don’t know which is the truth of how Mr. Lee had passed on. Supposedly he fell into a coma and never awoke? What caused this coma? Aneurism? Due to cocaine? Was it his electric stim shock?

From what I gather, my theory since he didn’t use weights to work out and manually squeezed his muscles for tension and with the use of stim muscle shock perhaps his body freaked out one night and his heart shut down for some strange reason, then turned back on but sent a popped vessel to the brain?

What is the truth?