Rewrite the following sentences without changing their meaning. Use the given word(s) if any.

The weather was bad. They had to delay the flight. (SO)

→ .............................

When the construction of a new database is finished, we will call you./We will call you when the construction of a new database is finished./When the construction of a new database is finished, we'll call you./We'll call you when the construction of a new database is finished.