A signals control officer in Germany was playing a game on his mobile phone shortly before two commuter trains collided in February killing 11 people, prosecutors said Tuesday, according to dpa. Prosecutors in the southern German town of Traunstein said they had issued an arrest warrant for negligent homicide against the 39-year-old dispatcher, whose name was not revealed in keeping with privacy laws. On February 9, the trains crashed into each other on a single-line track near the Bavarian town of Bad Aibling, in one of the worst rail accidents in German history. Four train drivers and seven passengers were killed and 85 people were injured. The signals officer confessed that he was playing a game on his smartphone at the time of the collision, Chief Public Prosecutor Wolfgang Giese said. The prosecution sees a direct connection between his playing of phone games and the cause of the crash. Investigators said that it was assumed that "the accused was distracted" from controlling the trains. As a result, he had given the trains false signals, they said. Investigators said the dispatcher was playing games on his phone for an extended period, until shortly before the collision.