for that reason; therefore; used to indicate that what follows is the result or consequence of the previous statement.
事故で道路が封鎖された。そのため、電車で行くことにした。
The road was closed due to an accident. For that reason, I decided to go by train.
彼は病気がちだった。そのため、会社を辞めた。
He was often ill. For that reason, he quit the company.
これは重要な問題だ。そのため、早急な対応が必要だ。
This is an important issue. Therefore, prompt action is necessary.