Fall at work

I fell whilst working at an airports cargo depot, where a well known delivery firms depot is.  Anyway the pavement was blocked by delivery men and carts and parcels etc so i stood on a wooden pallet to get past them but the pallet was broken and as soon as i stood on it it gave way and i landed on my knee.  I hadn't broken it or anything but my boss told me to go to hospital to get it checked out.  It was badly brusied and swollen and very sore but wasnt fractured they gave me a support bandage to wear.  I didnt want to lose any money by being off work (my company deducts money for the 1st 3 days off then you get full pay for 3 weeks)  so i went back to work the next day.

I wasnt going to claim but after receiving my pay slip they had took the a days wages off me for being off.  So do i have a case i did take pictures after i fell?  Who will be responsible my company, the delivery companys negligence or the airport whos property it is?  How much am i likely to get?

Thanks