KHUSHI'S CHARS Bianca di Angelo - all on her own somewhere on an outdoor deck enjoying any moonlight so she wouldn't realize right away that something is up until the boat starts to slow down
Kamala Khan - in the library at that moment, working on research for more fanfiction, halfway through writing a good starter on her laptop when it shut off and she let out a blood-curdling scream. >_>
Percy Jackson - was in the outdoor pool when he sensed something amiss in the waters and realized they were slowing down before any other people. He's going to want to check out the waters but he knows it's not smart to go down there alone himself, even though he can see everything even in the dark.
Nakia - in her suite. When the power went out, Nakia attempted to use the kimoyo beads to find the other Wakandans and made her way to Shuri's suite.
Spider-Gwen Stacy - was hanging out with Tim Drake when her spider-sense went haywire right before it, and she flipped out. Tim's gotten familiar with her spider sense by now, but when he raised an eyebrow at her, Gwen could just say "I have no idea", it's something. Before she could reach out to Ben, the network goes down.
Leslie Thompkins - in Roy and Lian's suite. Once the network comes back on, she tells them to hang tight while she went and checked on if anyone needed medical help of any kind.
H.R. Wells - is in his wheelchair, roaming around the hallways. Ends up getting stuck in the elevator when the EMP hits actually. He could use someone's help.
All my other chars are safe in their suites with their family, most likely. Roxie's with her parents, Arthur is with Molly, Allura is when Suite Voltron, etc.