LENOX — More than 1,000 National Grid customers lost power late Sunday afternoon, closing some businesses and disabling traffic signals along Route 7 and 20 (Pittsfield Road) from North Main Street to the Pittsfield city line.

Along with many residents in the northern section of town, the entire commercial strip on Pittsfield Road was blacked out, forcing some restaurants and stores to close down or to remain open for cash customers only.

National Grid responded to a failed transformer at 218 Main St. near the Keator Group building at about 4:45 p.m., said National Grid spokesman Robert Kievra. A small fire on the utility pole there was reported by Lenox Police.

Initially, 1,086 utility customers were affected, about one-third of the National Grid’s hookups in the town.

Crews isolated the outage to about 123 customers by 5:07 p.m., according to Kievra, and to 21 by 9:10 p.m. Power to all was restored by 3:42 a.m. Monday.

Most of the commercial corridor was still “in the dark” shortly after 6 p.m. as motorists seeking to cross or access the heavily traveled state highway were cautiously navigating the challenge.

There were no accidents reported during the blackout, according to the Lenox Police daily log.

Lenox Dale was not affected, since the village is served by Eversource.