Co51 was alerted for a roof collapse at the NIH Childrens’ Inn. E751 AT751 and A751 Responded. Recon found that part of the roof had collapsed onto the 2nd floor while contractors were working in the area. C751, C751B C751C C751D AOS. C751D established command. MCFRS Collapse Rescue Team was requested. MCFRS BC702 and SpOps Chiefs AOS. Crews worked with the contractors and brought in a crane to assist in removal of materials and shoring the roof system.