back at marge nixon's house, more volunteers came to lend a hand. here they call it the queensland spirit, and there's been plenty of that today, determined to clean up and rebuild this flood devastated city. ian williams, nbc news, brisbane. >>> when "nightly news" continues in just a moment, startling new disclosures from president reagan's son, ron, about his dad's alzheimer's disease. >>> later, someone who has been making a difference in tucson for years and how much this community needs her now. >>> as we approach the 100th anniversary of the birth of president ronald reagan next month, his son, ron, has written a new book with startling disclosures about when his dad's alzheimer's disease started to reveal itself. here's nbc's john yang. >> so help you god. >> so help me god. >> reporter: ronald reagan was the oldest president ever, 69 when he took office. he was diagnosed with alzheimer's disease five years after leaving the white house. but in a new book son ron reagan writes that as early as thre years into his first term, i was feeling th