Carrie Underwood admits she was terrified when her baby boy got locked in a car.

The 'Smoke Break' hitmaker's husband Mike Fisher was forced to break a window to free their six-month-old son Isaiah Michael from their vehicle in July after their dogs accidentally locked it from the inside.

Asked about the incident, the 32-year-old star said: ''It was such a random thing, we were at the airport.

''My husband and I both got out at the same time, and both shut the door at the same time, and immediately one of our dogs -- I still don't know what one it was -- jumped up on the control panel on the door. [We] heard the thing click, and I was like, 'The doors locked, the doors locked, the doors locked.' Nobody had a spare set of keys.''

After failing to open the doors without force, Mike ''ended up having to break the window.''

But Carrie claims her in-laws may never forgive her pets for the incident because it was their car.

She told Lisa Dent and Ramblin' Ray on their Chicago-based radio show on US99.5: ''I don't think our dogs will ever be invited back.''