Learn Dutch: Daardoor verlamde het netwerk direct. - As a result the network was paralysed immediately.

The sentence starts with the causal adverb daardoor (as a result). In Dutch, whenever you put something other than the subject in the first position, it triggers an inversion in the word order. The verb must stay in the second position, which forces the subject (het netwerk) to move right behind it.

The English translation says "was paralysed", so why is there no passive verb like werd in the Dutch sentence?

The Dutch verb verlammen can be used both transitively (to paralyze something) and intransitively (to become paralyzed). In this sentence, it is used intransitively to mean the network "became paralyzed". Because the verb itself carries the meaning of undergoing the change, you do not need a passive construction with a helper verb like werd.

Could I use daarom instead of daardoor here?

Not really. While both can mean "therefore" or "as a result" in English, daarom implies a logical conclusion or a conscious decision based on a reason. Daardoor indicates a direct, often physical or mechanical cause-and-effect. A network crashing is an involuntary mechanical consequence, making daardoor the natural choice.

Why is verlamde spelled with only one m, unlike its infinitive verlammen?