The pilots of flight PK8303, an Airbus A320 carrying 91 passengers and eight crew, were attempting to land at the city's Jinnah International Airport.
The plane had attempted one landing but as it went round again lost its engines and issued a mayday call.
At least two passengers are confirmed to have survived the crash.
One, Muhammad Zubair, has been describing his ordeal, recalling how he lost consciousness then woke up to smoke and screaming.
What caused the crash?
It has yet to be confirmed but here is what we know so far.
Flight PK8303 was approaching Jinnah International Airport at about 14:30 local time (09:30 GMT). It had been given permission to land but the pilots decided to abort and go around for a second attempt.
The reason is not yet known, but one civil aviation official told Reuters the plane may have been unable to lower its undercarriage. Images posted on social media appeared to show scorch marks under both engines, with no undercarriage visible on approach.