If my neighbor's pool is partially on my property, am I liable for injuries or deaths?

Your question poses the question in terms of your neighbor being the owner of an over ground pool partially upon your property. Your factual statement appears to state that you are the owner with the pool partially upon your neighbor's property. With respect to your liability for an injury or death, ownership could be very important. Other important factors would be how much of the pool is on your property, how the injury or death occurred, and whether the injured party entered the pool from your property or your neighbors. There are a host of other issues that may need to be determined however in many states as in the state of Kansas the ultimate issue would be one of negligence. For you to be liable there would have to be a finding that you were negligence and in the state of Kansas to prove negligence one would have to show that [1] there was a duty owed (such as safe guarding against defects regarding the pool, safe guarding against unauthorized use - attractive nuisances, proper supervision, etc), [2] that there was a breach of the duty (a failure to do what was incumbent upon you to provide for the safety of others) [3] that the injury or death was caused by your breach of duty, and [4] that someone was injured or suffered damages as a result of your breach. Considering the same if someone visiting your neighbor slip and feel into your neighbor's  pool and was injured it would be difficult to prove that you had a duty to the guest and therefore that you were negligence and thus liable for the injury; if your neighbor’s guest was injured in your pool then proving some duty upon you becomes easier to do and thus some negligence could be found; if the pool was your neighbor's but the guest was yours then you have the greater duty and the likelihood for finding negligence upon you is more likely than the afore stated scenarios; if both the pool and the guest were yours then the duty upon you would be the greatest of all thus stated and the ability to find you negligence poses the greatest risk for you. With regards to a liability release, indemnification agreement, hold harmless agreement or any such contractual arrangement, the same would not protect you as the owner or your neighbor as the owner if the nonowner is found negligent, however, such an agreement could, if properly drafted, provide a right to demand payment for the harm caused by the negligent party.

Yes, you can be liable. You can enter into an indemnification agreement with your neighbor, but if you get sued, good luck enforcing the agreement on your neighbor. this may affect insurance too.

Yes, if a neighbor's pool is on your property, you could be liable for death or injuries arising from a failure to adequately secure the pool against unauthorized use, such as by children--pools are considered "attractive nuisances," and there is an obligation to take affirmative steps to prevent unauthorized use. You could also be liable for failure to properly supervisor children lawfully using the pool; or if you have  BBQ or dinner party, serve drinks, and a drunk guest falls in; or from injuries caused by improper maintenance; etc.

A liability release is almost valueless in this case--children cannot waive liability, for example; you would need all guests or visitors to sign it; and in any event, you can't waive your  liability for actions of your which are considered grossly neglignet (more usually negligent or careless).

You could have the neighbors whose pool it is sign an agreement (if they will) indemnifying you against any claims--i.e. agreeing to reimburse your all liabilty and legal fees. But they may not do this; and if they did and refused to pay, you'd need to sue them to enforce it; and if they had no or little money (e.g. they were sued themselves and lost all), you'd have no effective recourse. A indemnification agreement is helpful, but it's hardly ironclad protection.

You should make sure you have adequate insurance, disclosing the existence of the pool to your homeowner's insurer--if you don't disclose, you may find that the insurer disclaims coverage. You should put up adequate fending around that portion of the pool on your property. These things, like the indemnification agreement, will help, but this is still a situation rife with potential liability for you.