The 85-year-old actress shared video images of a charred wall on social media after the weekend fire. She also tweeted thanks to the "marvelous" firefighters who tackled the "terrifying" blaze.
Collins said her husband Percy Gibson was a "hero" for trying to douse the flames with a fire extinguisher.
The London Fire Brigade said Monday that the blaze in the ritzy Belgravia neighborhood was caused by sunlight reflecting off a shaving mirror and setting fire to a bathroom blind. It said such fires were a particular risk at this time of year.
The brigade said Collins and Gibson were both checked at the scene but did not need hospital treatment.
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