Anirban DasGupta, Purdue University, writes:

Thriyambakam Krishnan, former Dean of Academic Studies and Professor at the Indian Statistical Institute, passed away in Chennai, India on July 4; he was 81. Jointly with G.J. McLachlan he authored the masterly and popular Wiley text on the EM algorithm and its applications. Dr. Krishnan, a PhD student of C.R. Rao, specialized in experimental design, classification, and unsupervised clustering during the early years. He served as consulting statistician to Systat and to Mu-Sigma in India. At the time of his death, he was still teaching courses in probability and statistics at the Chennai Mathematical Institute.