Today on CNN10: We'll turn back the clock for a look at one of the worst environmental disasters in US history, as we mark the 37th anniversary of the Exxon Valdez Oil Spill. Then, we'll see how an innovative new expanding foam could help change the face of emergency medicine, before learning the history behind one of Washington, D.C.'s most picturesque springtime traditions.Learn more about your ad choices. Visit podcastchoices.com/adchoices