Process refusing to die?

[NO645]

I'm getting the error seen below while trying to run the pitfill function on a tif formatted DEM. I was hoping someone might have some ideas about what is going wrong. The DEM is large (~400 GB), but I have 1 TB of memeory available. I'm also using 10 processes.

Thank you for any insight!

PitRemove version 5.3.8
Input file /p/work2/nolsen2/PA/PALIDARcrop1.tif has geographic coordinate system.
This run may take on the order of 811 minutes to complete.
This estimate is very approximate. 
Run time is highly uncertain as it depends on the complexity of the input data 
and speed and memory of the computer. This estimate is based on our testing on 
a dual quad core Dell Xeon E5405 2.0GHz PC with 16GB RAM.
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WARNING: A process refused to die despite all the efforts!
This process may still be running and/or consuming resources.

Host: lmem00
PID:  29677

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[lmem00:29675] 8 more processes have sent help message help-orte-odls-base.txt / orte-odls-base:could-not-kill
[lmem00:29675] Set MCA parameter "orte_base_help_aggregate" to 0 to see all help / error messages
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mpiexec noticed that process rank 3 with PID 29680 on node lmem00 exited on signal 9 (Killed).
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[dtarb]

You may still be exceeding memory available. See this file that works out memory requirements across all processes for various TauDEM programs. MemoryRequirements.xlsx. Broadly, for Pitremove you need RAM that is 4 x the input file size. However it is better to work this out using rows and columns than the file size, as TIFF may use compression. I am assuming that smaller files work for you, so there is not any other installation or library problem.