Officials who monitor electricity usage say they expect to have enough resources to meet peak demand as the summer continues — despite an ongoing heat wave.

According to Marcia Blomberg, senior media relations specialist for ISO New England, which controls the region’s energy grid, New England’s electric power grid has been operating normally throughout the heat wave so far, and it’s expected to continue.

But that’s just supply, which doesn’t mean equipment can’t break on a local level as residents crank up the air conditioning.

That’s what happened over the Fourth of July holiday. Early Thursday morning, 2,479 Eversource customers experienced power outages: 328 in Brookline, 451 in West Roxbury and a whopping 1700 in Brighton, according to Eversource spokeswoman Priscilla Ress.

Ress said the outage came in the wake of the holiday festivities, as everyone returned home and kicked on the AC.

“If you look at the time, you’ve got people who were probably coming home from fireworks and going indoors, cranking up the air conditioning, and it’s a lot of pressure, it’s a lot of strain that’s put on that system,” Ress said. “Sometimes things just break.”

The problem wasn’t caused by a lack of electricity, but rather a distribution problem: extreme heat caused a burden on the system, which resulted in an underground cable failure, which caused the outages, some of which lasted nearly six hours.

“With these kinds of conditions, it does put an excessive strain on a system,” Ress said, “and we work very hard to keep the system going and the power being delivered reliably.”

About 20 customers in Brookline also lost power overnight due to a tree that fell on a power line.

According to ISO New England, the grid expects to have sufficient capacity throughout the end of this week, when the heat is forecasted to break.