My great grandfather x2 was named Rocco Izzo, from Pietramelara (NE of Naples Italy). From what I've been able to gather, he came to NY to work on the railroad for a whille sometime around 1900. He sent money back to his wife (Maria Theresa Russo) in Italy monthly. He didn't stay long, and ended up returning to Italy. He never returned to the US.
His son, Carmine Izzo, came to NY in May 1914 to also work for the railroad. He ended up settling in Rome NY and working for Rome Cable. Carmine married Anna Insogna, and had 11 children.
The names in your family, are obviously very similar. I don't think it's a stretch to think Carmella and Rocco could be cousins or siblings of Carmine Izzo. Do you have anymore info on where exactly they came from? Parents names?