To give the news about the fact, was Fio-Cgil from Pavia,
the labor union to which Vecchia {belonged, was enrolled}
The Italian sentence lacks something very important: the verb in
the principal proposition;
this is ok only in very, very short sentences (made of only one proposition) where the implicit verb can easely be guessed at,
or in titles for newspapers reportages.
A dare la notizia dell'accaduto, {e` stata, fu} la Fiom-Cgil di Pavia,
sindacato al quale Vecchia era iscritto.
Another form is:
La notizia dell'accaduto {l'ha data la, e` stata data dalla} FIom-Cgil ...