Thursday's top 5 headlines: what you need to know

President Obama traveled to Orlando Thursday to pay tribute to the victims of the worst mass shooting in U.S. history, the White House said. Obama went to Orlando "to pay his respects" and to stand in solidarity with the community as they embark on their recovery. Labour MP Jo Cox has died after she was shot three times and repeatedly stabbed in an attack in her constituency near Leeds. She was 41-years-old. The attack was reportedly carried out by a man shouting 'Britain First'. Dallas Mavericks owner Mark Cuban will donate $1 million to the Dallas Police Department, which announced it will primarily use those funds to protect the LGBT community. The funds will pay for about 16,000 hours of overtime for the Dallas police to help the city’s counterterrorism efforts. The Cavaliers return to Quicken Loans Arena for Game 6 of the NBA Finals Thursday night and it will be one of the biggest sporting events fans have ever seen. No team in NBA Finals history has come back from being down 3-1. Years of research on dolphin behavior and pressure from animal rights groups has led the National Aquarium in Baltimore to move the marine mammals to a sanctuary. It will be the first of its kind for dolphins in North America.