Simplify the following text for a Grade 9 native English-speaking person.
Original: The latter is a difficult task , and only a few young have been successfully raised sinceâ '' notably at Healesville Sanctuary in Victoria . The leading figure in these efforts was David Fleay , who established a platypussaryâ '' a simulated stream in a tankâ '' at the Healesville Sanctuary , where breeding was successful in 1943 .
Simplified: David Fleay at the Healesville Sanctuary in Victoria had the first successful zoo raised platypus in 1946 .