The US Democrats are promising a celebration of President Joe Biden on the first day of their Convention in Chicago. But with thousands of pro-Palestinian protesters in Chicago tonight, could discontent over Gaza harm Kamala Harris's election prospects?Also tonight:The British tech tycoon Mike Lynch and five others are missing after a luxury yacht sank in a storm off the coast of Sicily. So what might have caused the superyacht to sink?Allegations that dozens of workers were trafficked by a small, family-owned, Scottish fishing firm.