I was dealing with a system failure, so I was late to the meeting.
I came late to the meeting because I had to deal with a system failure.
「システム障害」は英語で system failure となります。
「対応する」は英語で to deal with, to handle といえます。
1) I was dealing with a system failure, so I was late to the meeting.
（システム障害の対応をしていたため、会議に遅れました）
2) I came late to the meeting because I had to deal with a system failure.
（私が会議に遅れてきたのはシステム障害の対応をしなければならなかったからです）
I had to deal with a system failure を I had to handle a system failure とも言えますし、I was dealing with a system failure を I was handling a system failure とも言い換えられます。どうぞご参考に！
日本 
