A partial list of famous piping disasters:

Piper Alpha (1988, North Sea) - Offshore platform explosion, 164 deaths
Bhopal, India (1984) - Methyl Isocyanate release, thouands of deaths
Mina Al-Ahmedhi Refinery (2000, Kuwait) - flammable vapor release and explosion - 7 deaths
Petrobras (2001, Brazil) - Offshore oil platform explosion, 10 deaths, platform sank
Ammonium Nitrate Explosion (2001, Toulouse, France) - 31 deaths
Baytown, TX (2004) - Naphtha unit explosion and fire
Mojave Station - (1986) Hot Reheat seam-welded piping failure
Lodgepole Well - (1982, West of Edmonton) - not strictly a piping failure, but a failure of the drilling operation led to a release of billions of cubic feet of methane
Three Mile Island (1979, Harrisburg, PA) - blockage of a feedwater line led to a release of radioactive steam
Chernobyl (1986, near Kiev, Ukraine [then USSR]) - likely water hammer incident triggered failure of reactor cooling water flow, leading to a major release of radioactive material. Portions of the site are still off limits.