An English teen who drowned trying to rescue her Muslim boyfriend from a canal had been dating him secretly because of the religious difference, friends said.Sara Rylance, 17, and Fayz Uddin, 18, died Wednesday night in a canal in Birmingham, the Daily Mirror reported. The couple were with friends setting off fireworks in a celebration of Diwali, the Hindu festival of lights.The couple had become separated from the rest of the group when Uddin apparently fell into a lock with 20-foot-high walls. Rylance tried to reach him and slipped into the canal.Pete Millane, a spokesman for West Midlands Fire Service, said both were unconscious when pulled from the canal and efforts to revive them failed.\"The water in these locks is very cold this time of year and at that time of night and it quickly takes a toll on the human body,\" he said.Friends and family of both young people were shocked by the tragedy. Uddin was working as a waiter and Rylance was still in school.\"They had been together for a few months but kept it a secret because he was supposed to be with a Muslim girl,\" a friend said.