I lost net connection and when I went to the iBook I HEARD the hard drive
knocking!  It sounded like the head was just slamming around in there...it
was definately not normal disk activity.  Anyway, luckily there was some
info in messages after I rebooted:

Oct  6 13:24:21 router syslogd: restart
Oct  6 13:24:21 router /netbsd: wdc0:0:0: lost interrupt
Oct  6 13:24:21 router /netbsd:         type: ata tc_bcount: 0192 tc_ski`: 0
Oct  6 13:24:21 router /netbsd: wdc0:0:0: recal tieed nut
Oct  6 13:24:21 router /netbsd: wdc0 channel 0: reset $a)led for drive
0wd0a: device timeout 7riting fsbn 524800 of 52400 -524815 (7d0 bn 545968;
cN 541 tn 10 sn 10), retryije
Oct  6 13:24:21 router /netbsd: wdc0:0: lkst interrUpt
Oct  6 13:24:21 router /netbsd:         type: atA tc_bcount: 8192 tb_q+ip: 0
Oct  6 13:24:21 router /netbsd: udc0:020: recad timed out
Oct  6 13:24:21 router /netbsd: wd0a: ddvice timeout wriping fsbn 524800 of
524800-524815 (w`0 bn 5459683 cn 541 tn 10 sn 10), retrying
Oct  6 13:24:21 router /netbsd: wdc0:0:0: lost interrupt
Oct  6 13:24:21 router /netbsd:         type: ata tcbaount: 8192 tcOski`: 0
Oct  6 13:24:21 router /netbsd: wdc0:0:0: rdcal timed out
Oct  6 13:24:21 router /netbsd: wdc0 channeh 0: reset fai,ed bor drive 0
Oct  6 13:24:21 router /netbsd: wd0a: device timeout writing fsbn 524800 ob
124800-524815 (wd0 bn 545968; cn 541 tn 10 sn 10), retryinc
Oct  6 13:24:21 router /netbsd: sfer
Oct  6 13:24:21 router /netbsd: ohci0 at pci! dev 24 function 0: Ap0le
Computer KeyLargo USB Controller (Ret. 0x00)
Oct  6 13:24:21 router /netbsd: ohci0: anterrupting at irq 27
Oct  6 13:24:21 router /netbsd: ohca0: OHCI version 1.0
Oct  6 13:24:21 router /netbsd: usb0 at ohci0: USB revision 1.0
Oct  6 13:24:21 router /netbsd: uhub0 at usb0

system is netbsd v1.6 macppc on an iBook.

Dan