The Arizona Republic

Jul. 27, 2006 02:00 PM

NOGALES - Four undocumented immigrants were swept away and likely drowned Thursday when they got trapped inside a tunnel that runs beneath the sister of Nogales, Ariz, and Sonora.

U.S. Border Patrol agents and Nogales Police officers found 34 undocumented clinging to the walls of the tunnel about 5:30 a.m. and pulled them to safety. Four more were swept farther upstream and still missing, said Santa Cruz County Sheriff Tony Estrada.

The group apparently got inside the tunnel when the gates opened during a storm -- a sensor triggers their opening when water pressure reaches a high point, helping to prevent flooding. The border crossers got caught by fast-moving waters when a second storm hit, authorities said.

During times of heavy rains the drainage water can reach several feet high.

"When they went under the tunnel, they couldn't see the storm coming," said Border Patrol Agent Gus Soto.

A team of local law enforcement and federal agents are searching for the bodies, he said.

Undocumented immigrants often use the Nogales wash network to cross into the United States, particularly when the gates beneath the cities are open because of the heavy rain. On July 26, 2004, a Mexican woman drowned in the fast-moving wash waters, while her two daughters survived.

Rain was falling across much of the area Thursday. Rio Rico Fire Capt. Adam Amezaga said an intense storm that lashed the area apparently was even heavier south of the border.

The drainage tunnel and canal, which is part of the Nogales Wash, runs underground through the downtown areas of Nogales, Mexico, the port of entry and Nogales, Ariz., before the tunnel opens to the air about a half-mile north of the port.

The tunnel, canal and wash carry storm drainage north from Nogales, Mexico, which sits at a higher elevation, into Nogales, Ariz., past the city limits about five miles north of the border, and nearly three miles further until it flows directly into the Santa Cruz River.

The Associated Press contributed to the report