sentences:  Palazzo Parisio remained in use by the postal authorities until 4 July 1973, when the GPO moved across the street to Auberge d'Italie and the Central Mail Room, the registered letter branch and the Poste Restante moved to the former Garrison Chapel (a building now housing the Malta Stock Exchange).While it was the GPO, parts of Auberge d'Italie also housed other government departments.Following the murder of Karin Grech by a letter bomb in 1977, mail addressed to people who were perceived to be at risk of a similar attack was checked for explosives.