That looks like one of two things happened, either the LUV got VERY stuck and someone pulled it out with a chain around that crossmember or something big got well and truly stuck and the LUV pulled it out. Hard to say which, I've pulled a full size truck more than once with my LUV.
Slice that mangled chunk out, measure the frame width of another LUV for reference, stuff a hi-lift jack in there and get the frame back the right width (if even needed, hard to tell from pics) , then weld in a nice replacement piece. You could use plain channel iron, heavy box tubing, REALLY heavy DOM tubing, whatever you happen to have around. I'd bet the frame is at least a little tweaked given the amount of bow in that crossmember, but it split away the frame too so it might not be that bad. You take this as an opportunity to put in a really heavy rear cross member with some recovery points built into it like D-rings or something. Never know when you might need to pull a Jeeper out of trouble.
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95 Isuzu Trooper Daily Driver
86 Isuzu Trooper reliable backup
77 LUV 2wd stock beltway blaster (resting)
79 4x4 LUV project: 2.6L, 5spd, 31s (eventually)
MEPR: Man, my 4x4 makes all other LUVs look good