Thousands of people lost their lives in the 9/11 attack on the World Trade Centre 25 years ago, but the long-term impacts to people who experienced it are still being uncovered.Patti Sonntag was a student studying at university in New York on Sept. 11, 2001 when she volunteered to help the medical team and emergency services deliver aid at Ground Zero. More than two decades later, she has been diagnosed with a rare form of cancer called retroperitoneal liposarcoma, linked to toxic dust at the si