Hate to say it but the right front tire tells the story. The lack of tread on the outside edge of the tire indicates a front end problem long before the axle fell off. Lack of overall maintenance I'd have to say, First pics shows signs of rust where some part of the frame or bracket had moved off its original alignment too. Can't tell from the pic exactly what it is that's misaligned. This tractor has seen some abuse in use.
Loader frame/chassis bolts do require periodic checking for tightness, especially when a tractor is new. It's cited in the owner's and service manuals of most brands, and its generally good practice to check any bolts that are stressed during use, until a pattern of them NOT coming loose is established. Best practice and common sense.
As to a temp repair. Try a bottle jack, floor jack, farm jack, whatever is available and jack the axle back tight to the frame. Strap it in place with 2" ratchet strap or a come-along, or whatever you have available. Have a tow truck use their saddle to tow it or a dolly they can drop the front end into. Tow to wherever, repair, and check all bolts on entire tractor and keep doing that until you have a track record of what needs Locktite, etc. Get new wheel/tire(s), as needed and do a full service on it, and keep detailed records going forward. It will be as good as you treat it.
Good luck.