The 911 system, the system for reporting emergencies, failed late Sunday night in Montgomery County, but service had been restored by about 1:40 a.m. Monday, authorities said.

County fire department spokesman Pete Piringer said the system was working again, but callers might still get a busy signal.

He advised that callers unable to reach 911 should report emergencies directly to local police stations and firehouses.

Piringer posted a link on the fire and rescue Twitter feed to a listing of the telephone numbers for local police stations and firehouses.

It was not clear early Monday why the system had failed or how many people had tried to use it when it was not working.