CHICAGO (CBS) — Traffic was snagged at Lower Wacker Drive and Michigan Avenue downtown Thursday morning, as a gas leak erupted in a ComEd vault.

Fire crews responded to a gas leak in a vault at 111 E. Wacker Dr., beneath the Illinois Center complex, after ComEd crews working on the vault smelled gas.

No one was hurt in the area, and no buildings were evacuated.

But traffic was jammed as crews responded.