EL CENTRO – A Mexican citizen accused of driving a sport utility vehicle into a canal, killing six illegal immigrants, pleaded not guilty Tuesday to smuggling charges.

Alejandro Toribio Gama, who his attorney said is probably a juvenile, balanced himself on crutches as the brief proceedings in federal court were translated into Spanish, according to the Imperial Valley Press. He was arrested Sunday at a hotel near the crash.

His court-appointed attorney, Diane Regan, said she suspected Toribio may be 15 or 16 years old. A hearing was scheduled Friday to determine his age.

The GMC Suburban crashed Friday night in Westmorland, about 125 miles east of San Diego, with about 20 people inside, according to U.S. and Mexican authorities.

Among the survivors was a 12-year-old girl whose father, mother and younger brother died in the crash. Mexican authorities said the brother was 10; the California Highway Patrol said he was 8.

The family of four was from San Pablo, a village in central Mexico. The family had planned to join relatives in Los Angeles, said Francisco Torres, head of citizen protection at the Mexican Consulate in Calexico. They also had relatives in Alabama.

The girl planned Tuesday to return to her village, where her parents and brother will be buried, Torres said.

The family crossed on foot in the Imperial Sand Dunes, Torres said, a favorite spot for off-road vehicle enthusiasts. They were picked up along Interstate 8, which connects San Diego and Phoenix.