DARYN KAGAN, CNN ANCHOR: We have a breaking news situation, bringing you from Philadelphia, Pennsylvania, a building collapsed. This is the Regional Performing Arts Center where they were pouring concrete, reinforcing some rods and forms when the building caved in about 8:30 a.m. Eastern. An undetermined number of people were trapped; that, according to a police spokeswoman. At least three men covered in concrete have been pulled from the debris. And right before we came to you live with these pictures, courtesy of our affiliate KYW, we did see them pulling one man and putting him in an ambulance, taking him for help. The extent of the men -- of their injuries is unknown at this point. This center was meant to house 2,500 seats, a concert hall for the Philadelphia Orchestra, and also a separate recital theater. Work going on here, and obviously you can see the rescue operation still underway. We'll continue to monitor this and bring you more pictures and more information out of Philadelphia on this building collapse.
Workers Trapped at Philadelphia Construction Site