"This Is Us" is currently of the most watchable American TV series out there, which is coming to an end in the next few weeks. The comedy drama series is filled with light and sad moments, but the most heartbreaking blow to the fans was the revelation of Milo Ventimiglia's character Jack's death. Jack Pearson was certainly the best and one of the most influential characters ever, which was admired by all.

He was the kind of father every child wish for and since the news of this death broke out, fans have been losing their minds and trying to figure out what possibly could be the reason of his death. Fans have taken the deep emotional blow not so well and made a few theories on how Jack Pearson could have died. Below are mentioned some of the most intrigued theories.

Alcoholism: According to Bustle, everyone is aware of Jack's constant drinking habit and even though he seems to have quit the damn thing, there is still might be a possibility that it had already created some sort heart issues or lead to cancer as hinted in many episodes.

Heart Attack: Certainly, there is a lot going on in the family, and nothing for the best. Toby's heart surgery makes Kate very much distraught, but the storyline also showcased that her father might also suffer from a heart condition.

Plane Crash: As reported by Pop Sugar, this theory might be very upsetting, but as pointed out by Tumblr user 'Just-an-outlaw', Jack could have died of 9/11 plane crash. It is known that Kate and Kevin are afraid of flying while Randall resides in New Jersey and Rebecca resides nearby. Also, the family seemed to be moved to the city around 2001, which actually make a lot of sense, considering such as incident could take place.

Killed by Miguel: Surely it could be an accident as everybody knows his nature, but this could be the reason why Kevin hates him so much. Miguel was Jack's best friend and is the current husband of Rebecca.