Death of Salyut 2

I'd always heard that Salyut 2 was lost due to either an engine
explosion, or one of its RCS thrusters getting stuck in the on position
and spinning it to pieces via centrifugal force.
According to this: http://www.russianspaceweb.com/almaz_ops1.html
....what happened was the upper Proton stage cooked off (probably the
hydrazine) three days after separating from the station and created a
debris cloud in orbit with it, and a piece of that nailed Salyut 2 eight
days later.
Would this be the first spacecraft loss caused by space debris?
They were lucky that the first Soyuz mission to it was delayed, or there
might have been a crew on it when the collision occurred, as launch of
that was scheduled to occur ten days after the station reached orbit,
and the collision occurred on day eleven (the Soyuz would have also
entered the debris field as it approached the station).

Pat