(KMOV)-- St Louis firefighters are working to put out a possible fire underground.
Just before 9:30 a.m. Thursday, the fire department received a call about smoke in the Culinaria grocery store at 9th and Olive.
According to St Louis Fire Captain Dan Sutter, firefighter determined the smoke was coming from an underground Ameren Missouri vault at 10th and Pine.
Firefighters have blocked off the area near 10th and Pine as crews work to isolate and power down the vault.
It's unclear if there is a fire in the vault or another malfunction causing the smoke.
Capt. Sutter said that it is possible underground wires are arching.
There are no reports of injuries, according to Capt. Sutter.