Britney Spears' 7-month-old son, Sean Preston, was diagnosed with a hairline fracture on his skull after taking a tumble from a high chair on April 1. As they did when Spears was spied driving with the tot on her lap, child-welfare officials visited the singer's home after the latest incident "and determined there was no reason to open a formal investigation," Spears' attorney tells the Associated Press. "Nothing was improper."