mainshocks and larger aftershocks and as a result most of the earthquakes were found to be split in segments with the moment tensor's focal mechanism reading either a strike-slip on the fault which is west-east striking or normal faulting which is between rupture segments which also proves that the main characteristic of the quake is dextral strike-slip. From the timing of P-wave and S-wave arrivals at seismometers, there is strong evidence that the rupture propagated eastwards from the epicenter at speeds in excess of the S-wave velocity, making this a supershear earthquake. Impacts There was destruction caused in Yalova as a result of the earthquake, as well as hundreds killed and many buildings collapsed. Despite the earthquake being felt very strong there, the cause of most of the damage is suspected to be the induced liquefaction in the area. Since the area is mostly made of Quaternary alluvial soil which means it is rather prone to liquefaction, has around 200 drilling sites and boreholes and has many streams or rivers nearby, severe liquefaction was induced and recorded. Destruction in Istanbul was concentrated in the Avcılar district. Avcılar was built on relatively weak ground, mainly composed of poorly consolidated Cenozoic sedimentary rocks, which makes this district vulnerable to any earthquake. An official Turkish estimate dated 19 October 1999 placed the toll at 17,127 killed and 43,953 injured, but many sources suggest the actual figure may have been closer to 45,000 dead and a similar number injured. Reports from September 1999 show that 120,000 poorly engineered houses were damaged beyond repair and approximately 20,000 buildings collapsed, resulting in more than 250,000 people becoming homeless after the earthquake. About 60 Km of the Istanbul-Ankara highway, almost 500 Km electricity cables and over 3000 electricity distribution towers were damaged. Private contractors faced backlash for using cheap materials in their construction of residential buildings. Many of these contractors were prosecuted but few were found guilty. Government officials also faced backlash for not properly enforcing earthquake resistant building codes. Direct cost of damages is estimated at $6.5 billion US dollars, but secondary costs could exceed $20 billion. In 2010, the research branch of the Grand National Assembly of Turkey released a report stating the amount of casualties as 18,373. In the same report, they have stated that there have been 48,901 injured, 505 permanently injured, 96,796 homes heavily damaged or destroyed, 15,939 businesses heavily damaged or