October 10, 2008 4:28 pm Mercy Air Investigation The crash of a medi-vac helicopter raises concerns about the booming air ambulance business. US & World Videos 6:22 Pursuit standoff closes 91 Freeway in Anaheim Hills 0:40 Video shows aftermath of SUV explosion in Van Nuys parking lot 0:19 Fire burns at historic church in South LA 2:41 Hit-and-run driver severely injures 84-year-old woman in Hollywood 0:50 Legacy of Japanese American community leader who fought against drug abuse