Some fruit just naturally fall off, if the tree has more pollinated then it can produce. :o)

I tend to agree with katkin...many factors causes fruit drop. Wind also plays a role. Its been very breezy/windy lately. I'm assuming its the weak and not so healthy fruits that are dropping off. Possibly lack of moisture in the soil, personally we've had almost no rain here, though 10 year old trees doesn't require additional irrigation. My 5 year old tree last year drop quite a bit of small fruits too...its very disheartening to see what could have been :o(...guess its all part of mother nature's survival of the fittest...

I sympathize with your plight. I have two trees right now that are loaded with medium size ( early season Glenn ) and still smallish ( late season Valencia Pride ) mango's. There has been a bit more than the usual number of fruits dropping, but these are the smallest of the small, definitely smaller than walnuts and the Glenn with the most, but only about ten max. I attribute this to the high winds we have been experiencing the last 3 weeks but am not concerned in the least.
My favorite tree however, the Kent, is barren this year, not a hint of any fruit, so I guess we just have to put up with Mother Nature's quirks,...maybe next year ! ( smile )
Sounds like you have more of a dilemma tho. Like Puglvr says, a ten year old tree should be able to cope with higher than normal winds. Just hope your tree is OK and that this is just a temporary glitch.