Tens of thousands of people in central Prince George's County homes, schools and businesses remained under a boiled water advisory yesterday as the Washington Suburban Sanitary Commission worked to determine whether nearby construction or aging pipes caused the break in a water main Saturday. Tests on water samples taken from the 39-square-mile area affected by the break came back negative for contamination. If a second round of tests shows no contamination today, the advisory will be lifted, commission spokesman Mike McGill said. Meanwhile, 16 schools in the ... (more)