EL PASO – Chaos loomed when Immigration and Customs Enforcement agents dropped about 100 Central American migrants at the Greyhound station of this border city without notice Friday night. The families were in a strange city, many with little money and limited ability to contact loved ones for help. Then they were helped by angels. Ruben Garcia, the founder and director of the Annunciation House program that has housed and fed migrants for more than 40 years, knew since Wednesday that ICE planned to begin a new policy of essentially dumping migrants on border city streets. The migrants had been detained for several days in what are supposed to be short-term holding cells along the border in El Paso, and border authorities are struggling to cope with a fresh surge of Central American families coming to the United States to flee poverty, violence and corruption in their home countries.