On Saturday May 1, 2010, a coupling on the MetroWest Tunnel in Weston broke and began flooding into the Charles River. This led to the activation of the Chestnut Hill Reservoir through the Sudbury Aqueduct, which could have resulted in unsanitary water conditions in the greater Boston area. The Governor declared a state of emergency and an order for residents to boil drinking water was issued, and President Barack Obama signed an emergency disaster declaration offering federal help.

Click here to see a photo timeline of the incident and here for a real time showing of the break on video.

Click here for the compiled news archive relating to the break and subsequent boil water order.