Why has Karachi been named the ‘worst city to live in’; pollution or street crime?

What happened:  An annual report released by the  Economist Intelligence Unit  ranked Karachi as the world’s worst city to live in. It is pertinent to mention that the annual report ranks the living conditions in 172 based on nearly 30 factors, which are then categorized into five  stability, health care, culture  and  environment, education  and  infrastructures.  Details:  However, currently, Karachi has been ranked 168 and is only better than  Algiers, Tripoli, Lagos  and  Damascus.  On the other hand, the Austrian capital  Vienna  has been made the world’s most liveable city, and  the Ukrainian capital Kyiv  was not even included in the list.  More:  Express Tribune quoted the annual report by  EIU  as,  “Stability and good infrastructure are the city’s main charms for its inhabitants, supported by good healthcare and plenty of opportunities for culture and entertainment.”