In his 50-year career, Tom focused his research on understanding earthquakes and developing methodologies to mitigate their impact on society. Tom says that it was his good fortune to have found key talented collaborators who were also valued friends. The following paragraphs describe many of those collaborations in roughly chronological order. Research Summary Earthquake source physics and deformation mechanics of the crust; understanding the nature of strong ground motions during large earthquakes and the potential impact on buildings; understanding motions recorded in buildings; seismic early warning systems; design of seismic networks.