WESTMONT, Ill. (CBS) – About 1,600 customers in Westmont lost their electricity Wednesday morning, after power lines came down.

The downed power lines were on the south side of the railroad tracks near Cass Avenue in the western suburb, according to ComEd spokeswoman Arlana Johnson.

The outages began at 9:10 a.m., and as late as 11:15 a.m., about 1,600 customers had no electricity, Johnson said.

What caused the downed lines is not yet known, she said.

ComEd has had a crew on the scene working to restore power, Johnson said.

The areas affected originally were reported as from Naperville Road south to 57th Street, Richmond and Wilmette streets on the east to Cumnor Road on the west, according to Westmont police. As of about 11 a.m. police reported that the area of the outage had grown to Naperville Road south to 63rd Street, east into portions of Clarendon Hills and west to Cumnor Road.

If any residents need assistance because of heat or health-related problems, they should call police at (630) 981-6300.

The Sun-Times Media Wire contributed to this report.