A blast that killed 42 people at a Turkish state-run coal mine in mid-October was caused by a “chain of negligence”, concluded a police report seen by AFP on Thursday. The blast ripped through the mine near the small coal town of Amasra on northwest Turkey’s Black Sea coast on October 14. The concentration of methane in the mine exceeded the warning threshold of one percent on 85 occasions on the day of the accident, the report said. A mine employee said he was unable to reach the miners to warn them in the minutes before the explosion, citing telecommunication dysfunction and understaffing. “…