Boston’s water supply is interrupted for nearly 18 hours.

At approximately 9:30 a.m., a “catastrophic” break occurs in a 10-foot diameter pipe in Weston that forces water to be shut off at 6:15 p.m. to Boston and 29 other Massachusetts Water Resources Authority communities. The rupture sends 8 million gallons of water an hour into the nearby Charles River, raising its level by an estimated eight inches. Communities affected are forced to use untreated water from the backup Sudbury Reservoir and other sources for bathing and to boil water for drinking. Water service is finally restored at 5 a.m. on May 3, 2010.