On Christmas Eve, after a brutal winter storm had swept from one coast to the other and left millions of people in the dark - including 200,000 in the western and northernmost parts of New England - a series of events created an emergency situation for the regional power grid over a couple of hours that afternoon. Read more.

WBUR reports on the approval for Eversource's proposed East Eagle Street substation.

Eversource reports the lights went out for 855 homes and businesses along Morrissey Boulevard in the Savin Hill/UMass entrance area shortly before 9 p.m. The company says it hopes to have the power flowing again by midnight.

Waltham Police reported at 4"14 p.m.:

There are electrical surges throughout the City of Waltham that are causing transformer fires, light signals to fail, and smoke in buildings.

Updated 9:10 am., Tuesday.

Wednesday's expected temperature drop can't come soon enough for Eversource's groaning Boston power grid - and the people who keep losing their AC and lights because of it. Read more.

Several thousand customers across Somerville lost their power - and air conditioning - starting around 1 p.m., in an outage that also extended to part of East Arlington and which may not be fully fixed until after 8 p.m., Eversource reports on its outage map. Read more.

Eversource now says it could be around 11:15 a.m. before some 745 customers between L Street and Farragut Road get back the power they lost around 7:45 p.m. yesterday - although a few might not be able to turn their AC back on until 12:30. Read more.

A couple of manholes blew up in Savin Hill around 2:30 p.m. and the lights - and air conditioning - went out across Dorchester, from Lower Mills up to Port Norfolk. Read more.

Gretchen Van Ness reported this morning that the traffic lights on either side of the Neponset were out this morning - including at Fairmount Avenue and Truman Parkway, where Eversource reports a "vehicle accident" took out the power.