(KMOV) -- Most of the nearly 5,000 Ameren customers in the Shrewsbury area who were without power during a heat advisory on Wednesday have had their power restored as of Wednesday night.
The outage ranged from Shrewsbury on the north to Mehlville on the south.
About 400 customers in St. Peters area are without power Wednesday night. The outage area ranges from the Missouri River on the east to O'Fallon on the west.
No word yet on what caused the power outage.