3600×2 of machine real numbers takes up <60 KB packed or <350 KB unpacked. It's a small amount of memory. It's doesn't rule out a memory-related problem, since who knows what sort of operations you're performing. But even DistanceMatrix[] on the array takes up only 100 MB (packed).
I've experienced silent kernel crashes. I assume that's what you have. I'm not sure I've ever know what causes them. Mathematica can catch some things that request too much memory. I've sometimes guessed that an error occurs in a library, and the kernel is not prepared to deal with the consequences.
