The 43-year-old TV presenter has revealed that she and her husband decided to return home to the UK after Patrick, 49, was forced to hide from a gunman in a Los Angeles mall.
Cat - who has Milo, four, and James, two, with the comedian - shared: ''Fear was part of this.
''There was a moment when I was with a friend looking at potential schools for Milo and we had to ask the question nobody wants to: 'What do you do if there is a live shooter on the premises?' They tell you exactly what would happen, whether the kids would go to a safe room or hide under the desks, and you go... The danger suddenly becomes a reality.''
Cat's fears were intensified last summer, when Patrick and Milo were forced to take cover at the Century City Mall in Los Angeles.
Speaking to You Magazine, the TV star recalled: ''They shut down the centre. I got a call from Paddy, saying, 'They're taking us out through the fire exits but nobody can get to their car. If we walk to a junction, can you come and get us?'
''He wanted to keep Milo calm, so I didn't understand the enormity of what was happening. As I was driving I began to see helicopters, news vans, firemen and SWAT squads. It makes me go funny now. It was terrifying.''
Asked what they were like when she found them by the roadside, Cat - who is now living with her family in north London - replied: ''Paddy was shaken by it, more than Milo, who was hot and cranky but didn't properly understand.''
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