In baseball if a play ends and two base runners are at the same base who is safe and who is out? Does the situation change if one of the runners can be forced?
Technically the play cannot end with two runners on the same base.
If two runners are occupying the same base, then the trailing runner is considered "In Jeopardy", or able to be tagged out, and must either retreat to the previous base or, if it is occupied, the leading runner must advance a base.
However, if the trailing runner was forced to the base then the leading runner is considered "In Jeopardy" and must advance or be tagged out.
According to the Official Baseball Rules posted on MLB.com, rule 7.03 states:
My interpretation is that the following runner will be out in this situation unless he/she was the hitter and was advancing to a base - in that situation, the preceding runner needs to advance or will be tagged out.