A dog had a lucky escape after a freak block of ice as big as a football – thought to have fallen from a plane – plunged into the garden where he was playing just moments before.

Ham & High: Ice form a planeIce form a plane (Image: Archant)

Eveline Mache, 57, of West Heath Drive, Golders Green, said the ice crashed onto her patio on Saturday morning, showering frozen fragments across her garden.

She heard a loud crash outside just after she had let Ziggy, a six-year-old standard schnauzer breed, back indoors.

She went outside and found a large round ball of ice in her garden and about 30 smaller pieces the size of golf balls surrounding it.

Ms Mache said: “I’d just let the dog back in – if I hadn’t it could have easily taken him out. It landed right where he would have been wandering around.

‘‘I wonder if he hadn’t come back indoors whether he would have had a sixth sense to get out of the way.

“I assume it must have come from an aeroplane.

“My other half looked it up online and saw that this kind of thing can be caused by leaks on aircraft.”

In the last 40 years, there have been just five cases of people being hit by falling ice from a plane in the UK.

Aviation experts say the common misconception is that the ice is flushed toilet waste which freezes when falling to earth – as depicted in The Day Today sketch where a woman is struck by a falling urine icicle.

But according to the Civil Aviation Authority, the phenomenon usually occurs when liquid from air conditioning or pipes leaks from locked seals and freezes in the high altitude. When the aircraft descends, the ice begins to melt and falls off.

Ms Mache, who has kept the piece of ice in her freezer, said: “I heard an almighty noise that sounded like a really loud whoosh, then a crash and the sound of the fragments hitting the dustbins.

“I went outside and there was this great big lump of mashed up ice and fragments scattered everywhere.”

She immediately called on her 15-year-old son to find his camera and take some pictures.

“It must have been at least the size of a football before it shattered,’’ she said. ‘‘I’ve kept the largest piece in my freezer and it still measures about five inches (12cm) across.”