Understanding the meaning of 事情がわって


First, I would like to yet thank all the community for your great exchange
work ! I wish I can participate one day when I get a better understanding of
japanese language.

I am learning japanese as an autodidact and so i try different type of
exercices. One of them is to study some texts coming from the anime キャプテン翼
[Captain Tsubasa]. I put japanese audio with english subtitles.

In episode 2, 翼 (the hero) receives a letter from his father. We can see this
letter on screen, but the quality back in 1983 and handwritten style makes it
sometimes quite hard to decrypt. The aim of this question is not to ask for
translation of the letter, but rather understand some parts of it that I could
not do by myself despite my researches.

The context : 翼 receives a letter from his father explaining him that a famous
brazilian footballer has to come from Brazil and stay at 翼 house for a while.

In the letter, we find the following sentence (as least if i could read it
well) :  
事{じ}情{じょう}がわって当{とう}分{ぶん}の間{あいだ}、日本にいることになったんだ。  
[For personal reasons, he will stay at our house in Japan for a while].

I am there in trouble with the 事情がわって part. I can't understand what がわって
stands for. The best I could find is maybe the using of 変{か}わる verb which
might lead to [for changing reasons] or [because of a change in his state of
being]. But the problem is that 変 reads か, not が, so I think my explanation is
certainly wrong.

Does anyone have a better understanding of this word/verb ? It will be very
interesting to get any other point of view in order to understand this
sentence the best way.

Thank you in advance,

Natsu

