Writer Michael Crichton, whose blockbuster novels, films and TV series included “Jurassic Park” and “ER,” died in 2008, leaving behind an unfinished thriller about a volcanic eruption that imperils all life on Earth. Bestselling author James Patterson was tasked with completing Crichton’s book, and now, 16 years later, “Eruption” is finally being unleashed in bookstores. Correspondent Tracy Smith talks with Patterson, and with Michael’s widow, Sherri Alexander Crichton, about bringing back the voice of a master storyteller.