Edited sentence: It is believed that they were producing a piece for Vanguard at the time of their detainment.Laura Ling and her compatriot Euna Lee, were detained in North Korea after they allegedly crossed into North Korea from the People's Republic of China without a visa.Ling is the vice president of the Vanguard journalism unit.They were subsequently pardoned after former  US President Bill Clinton flew to North Korea to meet with Kim Jong-il