Two structures have collapsed following a period of heavy rains in the ancient Roman city of Pompeii, one the world's most renowned archeological parks, Italian authorities reported Sunday. A few stones fell late on Saturday from the Arch of Venus, a site that was already sealed off from visitors, dpa quoted conservation authorities as saying. More serious damage discovered Sunday morning was the crumbling of a 3.5-metre section of a wall at the Necropolis of Porta Nocera. Normally open to the public, the area was immediately sealed off. Culture Minister Dario Franceschini called a crisis meeting for Tuesday to assess the damage.