A San Francisco family that lost its six-year-old daughter, Sofia Liu, in a local traffic accident involving an Uber driver last month has now sued the smartphone-enabled black car firm for wrongful death. On December 31, 2013, Syed Muzzafar was using the Uber app while he was driving but did not have anyone in his car at the time of the accident. Muzzafar was also named as a defendant in Monday’s civil suit.