Tennis superstars Roger Federer and Rafael Nadal announce they have jointly donated Aus$250,000 (US$172,000) for Australian bushfire relief at a charity fundraiser in smoggy Melbourne. They were joined by a who's who of the tennis world, including Serena Williams, Caroline Wozniacki, Novak Djokovic, Naomi Osaka, Nick Kyrgios and Stefanos Tsitsipas.