Thousands of natural gas customers in Derby and Ansonia lost service due to a low-pressure issue Wednesday.

Officials say the system was shut off in an abundance of caution Tuesday night.

Eversource said it was working to restore customers' gas service and aimed to have a majority of customers restored by 11:59 p.m.

Officials said everything is safe and that there was no danger of an explosion.

Eversource technicians said they may have to enter individual homes to turn off the gas to make repairs.

Ansonia public schools were closed Wednesday as a result of the outage.