By Vassia Barba A homeless man has built a “ticking timebomb” cabin complete with washing machine and a treadmill in public park – after previously digging up the site with a stolen excavator in a misguided attempt to find buried treasure. Steven Irwin erected the survivalist structure, which is equipped with amenities including a washing machine and even a treadmill, within Dr Jose Rizal Park in Seattle. Irwin claimed he had permission to build it although authorities have denied it. The illegal cabin boasts fireplaces, propane heaters, multiple generators, and other utilities. Concerns have …