About 1,600 customers lost power early Thursday after the heat of the last few days caused an underground cable failure.
The outages affected Eversource customers in Brookline, Brighton, and West Roxbury, according to Priscilla Ress, an spokeswoman for the utility company. Ress said about 1,600 customers had been affected altogether.
As of about 6 a.m., an Eversource outage map online reported 149 customers without power.
About 20 customers in Brookline also lost power overnight due to a tree that fell shortly after midnight, Ress said, but those customers should not be affected by the current outage.
Felicia Gans can be reached at felicia.gans@globe.com. Follow her on Twitter @FeliciaGans.