"Gravity" Lawsuit

In 1999, a book called Gravity came out. In the book, a biohazard wipes out all the astronauts on the space station, except one woman. A rescue attempt ends in catastrophe, and the space station is left dangerously crippled. New Line bought the film rights, and then was taken over by Warner Brothers. In 2013, Warner Brothers released a film called Gravity. Warner Brothers say the two projects are completely unrelated. But the author, Tess Gerritsen, is suing. What’s her case, and what does it mean for other writers?