I have a machine at a datacenter, running 1.6.1:

NetBSD 1.6.1 (GENERIC) #0: Tue Apr  8 12:05:52 UTC 2003
    autobuild@tgm.daemon.org:/autobuild/netbsd-1-6/i386/OBJ/autobuild/netbsd-1-
6/src/sys/arch/i386/compile/GENERIC
cpu0: Intel Pentium III (Coppermine) (686-class), 930.33 MHz
total memory = 126 MB
avail memory = 110 MB
using 1644 buffers containing 6576 KB of memory

It crashed early this morning, and restarted.   It had been running for
35 days.

How can I tell why it crashed?  Whatever may have been on the console at
the data center is long gone.

I apologize in advance for asking such a basic question.

Thanks, -Mike