Certain specific techniques/technologies can be lost; examples:
certain Etruscan & Egyptian metallurgic techniques (this from a metalsmith friend)
China & certain mechanical technologies used in clocks, automatons, etc
the ability to read a given written language
(Etruscan, Minoan, Egyptian til the Rosetta Stone)
I'm sure there are others,but a lot of such
lost technologies are more due to a loss of social organization (try
building the pyramids without a central govt). About the only thing
that can kill a technology is
a total loss of knowledge (rare--the European dark ages were the
flowering of
Muslim culture) or loss of access to some vital resource.