The magnitude 8.8 earthquake that occurred in Chile on February 27, 2010, presents a unique opportunity to study the response of the modern built environment to large ground motions. Through support under this RAPID award, the George E. Brown, Jr. Network for Earthquake Engineering Simulation (NEES) equipment site operated by the University California, Los Angeles (UCLA), will send personnel and state-of-the-art monitoring equipment to Chile in March to gather strong-motion aftershock data from buildings and other structures as part of the NSF-supported Earthquake Engineering Research Institute (EERI) post-earthquake reconnaissance team. The UCLA team will deploy two 24-channel digital monitoring systems at initial monitoring sites to be selected with the EERI team and collaborating Chilean researchers. With Chilean support, the UCLA team will then deploy the monitoring systems on multiple structures for an initial two-week period. One of the monitoring systems will remain on structures in Chile through March and April, and be operated by newly-trained Chilean university staff and students. Data and equipment will then be retrieved during a second trip by one of the UCLA NEES staff in early May. The primary objectives of this RAPID award are the following: (1) to gather timely important data on the response of damaged and undamaged structures to strong shaking during aftershocks, (2) to provide a structural monitoring resource for the EERI post-earthquake reconnaissance team and Chilean researchers, and (3) to demonstrate the use of NEES resources for post-earthquake studies. Results of the monitoring will be posted on a web site as they are completed and widely publicized so that interested researchers will have access to information about these activities. This award is co-funded by the NSF Office of International Science and Engineering (OISE).