The girl leapt from the top floor of an abandoned hotel in the city of Cittadella on Sunday afternoon, the site of another teen suicide in 2008, La Stampa reported.
The prosecutor of Padua has now opened an inquiry into her death after reports surfaced that she could have been the victim of online bullying, Corriere della Sera said.
The teenager reportedly faced abuse on Ask.fm, a social networking website where users can post questions to others.
One person allegedly sent her a link to a trailer for the film Suicide Room, while another was quoted in La Stampa as saying: “I hope that one of these days you cut an important vein in your arm and die!”
In a final post, the girl wrote, “Enough stupid world,” La Stampa said.
She left a letter addressed to her grandmother, who raised the alarm but could not reach the girl in time, the newspaper reported.
The suicide comes as Italian politicians bring proposals to parliament to address cyber bullying.
MPs from Italy’s Democratic Party (PD) will this week outlines proposals to give authorities greater powers to remove offensive content from social media, blogs and news websites.