All lights within SCP-1355 are to remain on for twelve (12) hours each day
SCP-1355 is a one-story building
There is numbering inconsistency here. What I mean is that, the way you are writing numeric amounts is inconsistent, such as writing one numeric amount as 'twelve(12)' and the other one 'one'.
SCP-1355-1 report hearing a chorus of ethereal voices
The tone here is a bit iffy, since 'a chorus of ethereal voices' is not exactly something you'd read in a scientific article like this. Perhaps you can better state it as 'report hearing multiple voices often described as 'ethereal' and a 'chorus'' Or something like that? I'm not honestly sure myself.
I don't personally agree with this, because I'm pretty sure the foundation is far more mature than 'oh no bad words'. If you insist, at least put it like [EXPLICATIVE REMOVED].
However, at the end, all it does is… kill them? I don't really understand at all… I thought it was 'building up' very well but the payoff was disappointing. No vote.