It was revealed Tuesday night what actually set the Pearson home ablaze, sending countless other theories down the drain. Spoilers for the Jan. 23 episode of This Is Us. A faulty crock-pot is the fire culprit that has been long speculated upon, meaning that the faulty breakers and electrical box apparently have nothing to do with Jack's death. One pivotal clue still likely comes into play, though — how does the smoke detector on This Is Us fit into the new slow cooker information?
Well, obviously if the smoke detector doesn't go off (and it won't, as Rebecca and Jack forgot to buy batteries last week), that means there's less time that the Pearsons have to react before the fire spreads and becomes at best, unmanageable, and at worst, inescapable. The fire spread quickly from the slow cooker, across the kitchen counters and up the curtains. Before much time passed, it was across the living room and up the stairs. Fire is scary that way — there's no controlling it once it gets to a certain point, and it can get to that point in the blink of an eye.
As seen in the previews for next week's episode, Jack apparently opens a door — perhaps the one leading from his and Rebecca's bedroom into the hallway — and is immediately hit with a blast of smoke and heat. It's obvious that the smoke detector doesn't act as it should, that the fire is a deadly foe from the moment Jack lays eyes on it. Apparently we can also deduce that the Pearsons perhaps also don't have a smoke detector on the second floor of their home, which, in hindsight, isn't a great idea, especially since Jack is a contractor.
It remains unclear if Rebecca will realize after the fact that their smoke detector was without batteries. She'll be destroyed by Jack's death and likely desperately just trying to survive without him — she won't be thinking about old grocery lists to see what things she'd overlooked that may have prevented it. It's difficult to say how much, if any, of the house is salvageable after the fire. From the glimpse viewers got of the home at the end of the Season 2 premiere, it was burnt to a crisp and it'd be surprising if anything would have survived, making it unlikely that the smoke detector would still be there to be examined.
The firefighters, who are trained to assess such lapses in fire safety, could possibly be more focused on trying to figure out what actually started the fire, rather than rummaging through rubble and taking close looks at smoke detectors. It also doesn't appear that Rebecca harbors much, if any, guilt regarding Jack's death, which probably wouldn't be the case if she knew that he may still be alive had she just purchased some batteries.
But, you never know. Rebecca's always seemed to be able to take care of herself despite everything, so she may have worked through this realization long ago and come to peace with it. After all, Jack forgot to buy the batteries too. It wasn't a horrifying oversight in the moment. This show is, after all, about how the smallest details can have the biggest impacts. The smoke detector was one of them.
Now, Randall and Kevin seem to be following in Jack's footsteps, putting those carpentry genes to the test by renovating apartments and fixing up homes themselves. Might I suggest that they spend a little extra time to learn about circuitry, electrical wiring, and fire safety? Obviously the fire was no fault of Jack's and there wasn't really any way of anticipating it, but with the heartbreak and struggle that exists in this group already, let's try to avoid repeating Pearson family history.