Competitor's website down, how to gain advantage?

I just noticed that the website of my competitor, which is ranking above me for some keywords, is currently offline. It's probably expired hosting and I think it's gonna take them a few days to notice and fix the issue. Is there anything I can do to take advantage of this? I was thinking about using an indexing service to trigger a Google Crawl, but I don't even know if it's going to work. Any ideas?

discussing negative SEO is forbidden

there's nothing to do,
SEO is a long term game,

even if he get affected for a couple of days, it will be only a temporary effect,
he'll get back the rankings and most of the traffic after a couple of days,

your idea is just bad, attacking your competitors for any reason is just non-human,
even if it's legal, you're simply trying to harm someone that did nothing to you,

focus on your work & website(s)

Okay, thanks. I just wanted to know... Also had a website that was hosted on server which crashed and I noticed it after like a month when the website was already deindexed, after I started the server up it regained it previous positions in search rankings.