An Israeli construction innovator was jailed over the deadly 2001 collapse of a Jerusalem banquet hall. Jerusalem District Court on Thursday sentenced Eli Ron, who invented the construction material Pal-Kal, to four years in prison and handed 22-month terms to two other engineers. The three had been convicted in connection with the collapse of the Versailles banquet hall that killed 23. The building was built with Pal-Kal, which was found to be too flimsy to support the required weight. The engineers are expected to appeal the sentence.