It's amazing that the show made an episode about 9/11, but kept said episode timeless and more universally applicable, by not making it about 9/11, and instead came up with a more local, much more digestible incident and how it affected the people around it.
I mean, a building on fire, traumatic memories, treasured possessions being lost, as well as fearing for a loved one, are much more understandable to a kid than a national tragedy, and are things most people probably go through in their lives at least once, or at least have a frame of reference for. So, yeah, it's honestly impressive.
I could see the show perhaps have a similar episode if there was a big incident in the US with lots of media coverage, like a train crash or hurricane or something, but it wouldn't be the same, and likely have a different framing and narrative.