Get the tissues out.

Look, I don’t have to tell you that This Is Us is the emotional rollercoaster ride we all need right now.

Look, I don't have to tell you that This Is Us is the emotional rollercoaster ride we all need right now.

Nbc / Ron Batzdorff / NBC

And if you’ve been keeping up, then you know World’s Hottest and Greatest Dad™, Jack, dies at some point in his kids’ lives.

And if you've been keeping up, then you know World's Hottest and Greatest Dad™, Jack, dies at some point in his kids' lives.

Nbc / Paul Drinkwater / NBC

And a new fan theory suggests that Jack may have died in the 9/11 attacks.

NBC

Here’s the evidence: 1) Kate gets really freaked out while on a plane, and 2) we see Kevin destroy all of his model planes at some point in his childhood. Plus, 3) Randall works in New York City, and he and his mom live in a nearby suburb, which means the family likely grew up there, and Daddy Jack could’ve gotten a city job at some point.

Here's the evidence: 1) Kate gets really freaked out while on a plane, and 2) we see Kevin destroy all of his model planes at some point in his childhood. Plus, 3) Randall works in New York City, and he and his mom live in a nearby suburb, which means the family likely grew up there, and Daddy Jack could've gotten a city job at some point.