13 people were killed at a drug rehabilitation clinic in Tijuana on Sunday, a sign that the relative peace there celebrated recently by Mexican Presiden Felipe CalderÛn himself might be fracturing. The New York Times reported that the killings in Tijuana followed the shootings of 14 youth at a party Friday night in nearby El Paso. These series of killings are thought to be tied in with the largest load of marijuana ever seized in the country’s history.