A building in Brooklyn collapsed, killing at least four people, prompting an investigation into the cause. The incident occurred early Tuesday in a residential area. Emergency services responded swiftly, but the structure’s instability made rescue efforts difficult.

Authorities confirmed the collapse involved a multi-unit residential building. Initial reports suggest the incident may have been linked to structural failures. The mayor of New York City has announced a full review of the incident, emphasizing the need to identify those responsible.

This is the second major structural failure in the borough this year. Previous incidents have raised concerns about building safety regulations. Officials are now reviewing building codes and enforcement practices. The investigation is ongoing, with no official cause determined yet.