Mystery by the River Lea

This isn't technically in Harringay but I'm wondering if there are others who cycle or walk along the River Lea path who might be able to throw some light on this.

This morning I cycled south down my usual delightful route along the River Lea path on my way to work. Nothing untoward. Cycling back home in the late afternoon I got to the boathouse round about here and found an absolutely huge tree had fallen down and blocked the path. It was enormous: lying on its side the trunk was almost as high as my head. It was jutting out into the river and would have destroyed any canal boat unlucky enough to be by the riverbank (though it didn't look like this had happened).

The mystery is how this whopping great tree came to be horizontal in the space of about eight hours, on a day when there wasn't enough wind to blow over a much smaller tree, with no visible cuts that had been made into the trunk and no evidence that any machinery had been used to push it over. It looked like it had been uprooted, but by what and for what reason?

Insights? Conspiracy theories?