(West Linn, OR)  --  A 90-year-old man is being hospitalized for critical injuries, after a large tree fell on top of him at an adult-care center in West Linn.  Tualatin Valley Fire & Rescue says the man was standing outside the facility in the 20-thousand block of Willamette Drive yesterday when the 20-plus-foot tree toppled over.  Officials say the reason the tree fell was age-related, rather than weather-related.