Events detected by underground detectors on February 23, 1987

Principles of search and observation of neutrino radiation from stars which have experienced gravitation collapse are described in the article, design and parameters of all neutrino underground detectors which were in operation on February 23, 1987 are presented and report of experimental results from different detectors for that day is given. Analysis for agreement of experimental results of different detectors between each other and with the theory predictions is conducted. Question, related to the possibility of interpreting events in the underground detectors on February 23, 1987 as recording the neutrino radiation from 1987 A supernova is discussed