Beijing , China ( CNN ) -- Investigators were trying to determine Wednesday what caused China 's first fatal passenger plane crash in almost six years . A Henan Airlines flight with 96 people on board overshot a runway and crashed Tuesday night in the Yichun area of northern China , state media said . The plane broke into two pieces and burst into flames . On Wednesday , the government downgraded the death toll from the crash from 43 to 42 after a body that was torn apart was discovered to have been counted twice , according to the state-run Xinhua news agency . Fifty-four people survived . Five children injured in the crash were in critical condition , said Xinhua , citing doctors in Harbin , the capital of Heilongjiang province , where they had been transferred . Another 10 people were severely injured , it said . `` The coming 48 hours are the dangerous period , '' said Wang Yongchen , deputy head of the No . 1 Hospital affiliated with Harbin Medical University . Four of the children suffered heavy respiratory tract burns , said Wang . The investigators ' initial focus was to find the flight data recorder -- commonly known as the `` black box '' -- that might yield clues as to what caused the Brazilian-made Embraer 190 jet to crash land in heavy fog on a patch of grass about 1.5 kilometers ( 0.9 miles ) from the runway . The black box was found on the ground Wednesday morning , Xinhua said . Some passengers were thrown from the plane upon impact , according Xinhua , which cited the head of the publicity department of the Yichun city committee of the Communist Party of China . Chinese Vice Premier Zhang Dejiang led a team of transportation , health , work safety and security officials to Yichun after the crash , state media said . Two survivors told local television that the plane shook violently before it crashed and that thick smoke entered the cabin soon after impact . They said passengers were unable to open emergency exits after the wreck ; survivors escaped through cracks in the fuselage . The plane was carrying 91 passengers , including five children , and five crew members when it crashed at 9:36 p.m. ( 9:36 a.m . ET ) , according to Xinhua , which cited a source with the Civil Aviation Administration of China . The Henan Airlines flight had taken off from Harbin on the 360-kilometer ( 225-mile ) flight to Lindu Airport , about 9 kilometers ( 5.6 miles ) from downtown Yichun , a city of about 1 million residents near the Russian border , Xinhua said . A Yichun vice-mayor told Xinhua that most of those taken to hospitals did not have life-threatening injuries . China 's last fatal passenger airline accident occurred in November 2004 , when a China Eastern commuter jet took off in frigid Inner Mongolia without de-icing and crashed shortly afterward into a nearby park , killing 55 people . CNN 's Steven Jiang contributed to this report .
NEW : 5 children in critical condition . The death toll is down from 43 to 54 . 5 people survive Beijing 's first crash in almost six years . Survivors cite violent shaking prior to impact .