Haruka is going to go out investigating not long after the power goes out, which means she'll be on hand for taking out any raptors that cross her path/heading towards the source of anybody screaming/etc. However, her powers as Sailor Uranus take a toll on her the longer she uses them in Marina, so the longer she spends out in the fray (and she'll spend as long as she can will herself to - she'll be trying to find the source of all the weird bad energy/raptors/etc) the greater the chances of her getting seriously injured or even needing to be bailed out herself.
So basically - run into Haruka towards the beginning of the day, she'll be very useful. Run into her later in the day, she'll be a pain. (And probably in pain, but she'll stoic her way through it until she can't ignore it any more.) Prepare to deal with a lot of angst regardless, since ending up powerless pretty much IS her greatest fear.