Collapse of built environment

Four people ​were killed after scaffolding collapsed at ‌a construction site in the courtyard of a residential apartment building in the upmarket ​ninth district of Vienna, a ​police spokesperson said on Tuesday.
The cause ⁠of the collapse and the exact ​nature of the work that had ​been taking place were not immediately clear, the spokesperson said, adding that the building was ​an old one typical of the ​area, where much of the architecture is from ‌the ⁠19th century.
A spokesperson for the ambulance service said a fifth person, a 45-year-old man, was seriously injured.
The street ​the accident ​occurred on, ⁠Porzellangasse, runs through the heart of the district, near ​the city's French school and ​the ⁠nearby Palais Liechtenstein, one of the city's most opulent historic palaces.
Police are interviewing ⁠witnesses, ​including construction workers who ​survived the accident, the spokesperson said.
Reporting by Francois ​Murphy; Editing by Alison Williams and Nia Williams