Definition: In this task, a passage will be given and the goal is to identify an event from the passage. An event is defined as a single word representing something that happened, is happening, or may happen. An event can be factual or hypothetical, positive or negative, certain or uncertain. While most events are based on verbs, an event can also be based on a noun (ex. storm, snow, rainfall) or a copula verb (is, was, been, etc.). The event must not be a pronoun or an adjective. For noun events with multiple words, use the last word in the phrase as event.
Input: Passage: A four-storey building under construction in the Senegalese capital Dakar collapsed, killing two workers and injuring three others, hospital sources said Wednesday. Tuesday's accident came just a week after two old buildings tumbled down in Dakar and the northern town of Saint-Louis, killing two other people.

said