Due to the COVID-19 pandemic, we postponed the conference to April 2021, but with continuation of the pandemic we are now forced to cancel the physical meeting completely. We are disappointed to not meet you in San Juan, but together we produced an excellent proceedings volume which is available for free download at https://digital.lib.usf.edu/SFS0070630/00001. An initially planned second edition of the proceedings, planned for the April 2021 date, will not be produced since that date is now cancelled. At this time, we do not know when or where the next Sinkhole Conference will occur. We will wait until there is general certainty that the pandemic will be over in a reliably predictable timeframe before we begin planning. We thank you for your understanding and support, and we wish you good health. The Organizing Committee of the 16th Multidisciplinary Conference on Sinkholes and the Engineering and Environmental Impacts of Karst.