Mark J. Terrill / Assocated Press
Crews pour concrete to lay the foundation for the New Wilshire Grand building in a record attempt for the largest continuous concrete pour in history, Saturday, Feb. 15, 2014, in downtown Los Angeles. The marathon pour is expected to last 20 hours without interruption. The attempt will be verified by an official from Guinness World Records. The New Wilshire Grand will be the tallest building to be built west of the Mississippi and is expected to be completed in 2017.