system
Given the following post, respond as if you're commenting on Reddit:
human
Where were The Avengers on 9/11?

Less specifically, how did the Marvel Universe deal with 9/11?
gpt
The first plane strike looked like it may have been an accident; it wasn't until the second was too close to stop that it was absolutely apparent it was a deliberate attack. That was not a lot of lag time. Marvel does have superheroes that could still have stopped the latter planes (even with the very short response time), but those that were active (Sentry, Thor) were not in the area. The capes in NYC and DC (ex., Captain America, Spider-Man, Daredevil, possibly Luke Cage) are great heroes, but "stopping a hijacked airliner" was out of their capabilities. They did, however, do a great job aiding the police, firefighters, and medical personal responding to the disaster.

[Also look at Amazing Spider-Man #36]