Preparations for Israel's official Holocaust Memorial Day service have been halted by tragedy after a structure collapsed, killing one person.

Initial reports suggest that a lighting rig broke at the site of Mount Herzl in Jerusalem.

It is believed that a young woman was killed, while at least 20 others were injured, some seriously.

Tomorrow the country marks its annual commemoration to the six million Jews murdered by the Nazis, known as Yom Ha'Shoah.