July 4 celebrations put America on high alert
NEW YORK (ABC News) - It's a Super Bowl test for America's national security. Celebrations marking the nation's 239th birthday are facing what some call the most serious threats since 2001. The threat stream is very high, Los Angeles Deputy Police Chief Michael Downing said Friday. In fact, we don't think it's been this high since 9/11. From Los Angeles to Washington, D.C., Chicago and Boston th...