MEXICO CITY, Mexico (CNN) -- The driver of a truck that collided with a bus in northeast Mexico, killing 12 people including 11 passengers from the United States and Canada, was intoxicated, a Mexican official said Tuesday. Emergency workers wheel a crash victim on a gurney after Monday's bus crash in Mexico. The tractor-trailer's 21-year-old driver was among those hospitalized after Monday's crash near Monterrey, Mexico, said Segismundo Doguin Martinez, a police official in the Mexican state of Coahuila. The driver of the bus was among those killed, and 15 bus passengers were injured. The Senda Express bus, operated by Grupo Senda, had been traveling from McAllen, Texas, carrying tourists to Zacatecas in central Mexico.
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NEW: Tractor-trailer driver, 21, was intoxicated, official says
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18-wheeler swerved into oncoming traffic, official says; side of bus sheared off
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Death toll at 12: Eight from U.S., three from Canada, and bus driver, from Mexico
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Victim's daughter in Iowa says consulate called at 1:30 a.m. with word of crash
Seven of the injured @placeholder are from Texas and one is from Iowa, the newspaper said.