[umpharp]

This is a play that happened at a recent Jr College tournament.
I wasn't there, but one of the umpires involved was discussing the play with a group of us during a break in another recent tournament.
I'm curious what the correct ruling would be.

R1 on 1B. 1 out.
Catcher obstructs B2 during her swing. Ball ends up grounding towards F4.
R1 Interferes with F4 making the play.
BU kills the play.
What happens next?