California’s first known death associated with vaping marijuana was announced Friday by Los Angeles County health authorities. That same day, national health officials discouraged the use of e-cigarettes until they determine the cause of about 450 reported cases of a severe lung disease that has killed at least five people. In California, the Department of Public Health is currently investigating 62 potential cases of the disease in people with a recent history of vaping. An estimated 9 million adults and 3.6 million teenagers across the country use vapes, and a government survey last year found one in five teens reported vaping in the previous month. Forum talks about vape use and the potential dangers.