Learn Dutch: Doordat de aardbeving hevig is, stort de oude toren in. - Because the earthquake is severe, the old tower collapses.

While both can be translated as "because", doordat is used specifically for an objective cause or a direct, physical consequence—like an earthquake causing a building to fall. Omdat is usually used for subjective reasons, choices, or human motivations (e.g., "I run because I want to be healthy").

Why does the second part say stort de oude toren in instead of de oude toren stort in?

In Dutch, the verb must be the second "idea" or block in a main clause (this is known as the V2 rule). The entire dependent clause (Doordat de aardbeving hevig is) counts as the first block. Therefore, the main verb (stort) must come right after the comma, causing it to swap places with the subject (de oude toren).

Where does the word in at the end of the sentence come from?

It is the prefix of the separable verb instorten (to collapse). When a separable verb is the conjugated (active) verb in a main clause, the core part of the verb (stort) takes the second position, and the prefix (in) gets kicked to the very end of the sentence.

Why does oude have an -e ending, but hevig does not?