California chemical tank has cracked, causing state of emergency, thousands to evacuate  NPRExplosion threat at southern California chemical tank eliminated, firefighters say  The GuardianThousands still evacuated near Southern California chemical tank despite eased explosion fears  PBS"Still a potential" for chemical leak in California's Orange County after overnight operation. What to know.  CBS NewsCrack Forms in Toxic Chemical Tank, a Positive Sign for Firefighters  The New York TimesOverheating chemical tank in California no longer at risk of exploding, fire officials say  ReutersCalifornia officials race to avoid chemical tank explosion, thousands evacuate  USA TodayWhat we know about the chemical tank incident in Southern California — and what questions still linger  NBC NewsAll evacuation orders tied to Southern California chemical tank lifted after 'worst-case scenario' averted, officials say  ABC News - Breaking News, Latest News and Videos