A small aerial drone owned by the Mexican government crashed into an El Paso, Texas, backyard Friday. No one was injured. Authorities say the aircraft was likely conducting surveillance on cross-border drug and human smuggling, and the plane was returned to officials in Mexico. "Our law enforcement has a very close relationship with Mexican authorities," said a spokesman for a Texas congressman familiar with the matter. People familiar with drone technology say the aircraft probably ran out of batteries in flight, or may have lost radio contact with its operator.