A few tsunami have involved human actions, and thus may involve individual or corporate liability. They tend to be relatively small events, but usually occur in settings such as harbours where economic losses and loss of life are maximised. Two classes of event can be recognised:

Particularly during construction work. The clearest example of this occurred on the evening of November 3rd 1994 in Skagway, Alaska: construction of a railroad dock extension overloaded the sediments on which it was built and about 1 million cubic metres of rubble and sediment slid into the fjord on which the harbour is located. The resulting tsunami was up to 12 m high as it surged across the harbour. In addition to the $20 million loss (including wave damage to the 60% of the wharf which remained) and one death on the dock itself, around $2.1 million of tsunami damage was caused to small boats and a ferry terminal. Fortunately, the terminal was unoccupied at the time: it was swept clear by the wave and tens of deaths could have resulted if the collapse had occurred during the day. Another example of such a collapse occurred at Nice Airport, France, in 1979, where a much larger submarine landslide was triggered by collapse of a runway extension under construction. Tsunami up to 3 m high caused damage along 30 km of the French Riviera, and several deaths.

An ammunition ship carrying explosives equivalent to 2900 tons of TNT blew up in Halifax harbour on December 6th 1917, destroying much of the town by airblast but also generating tsunami which caused significant damage and a number of deaths outside the blast zone. Wave runups of several metres were recorded in these more distant areas. With explosive cargoes (bulk nitrate fertiliser, Liquified Natural Gas (LNG), ammunition, etc.) equivalent to up to a few tens of kilotons now common, significantly larger explosion – generated tsunami are possible and will cause damage over proportionately larger areas relative to the airblast damage area, because of the different attenuation functions for tsunami and body waves (see below SECTION CROSS - REFERENCE TO "ATTENUATION FUNCTIONS").