According to family members (story passed down) Cammillus was killed by a runaway wagon team. According to the Probate Record from Massac County pg. 36, which includes a copy of Doctor Bill for Family of Cammilus Trumbo to Dr. Joseph Brown (April 8, 1869 - June 7, 1870), Cammillus visited the doctor June 3, 4, 5, 6, and 7th 1871 for "visit and medication." No further entries after June 7th. This leads me to believe it is possible that the death was not instant. His death date is listed as June 7, 1871. Possibly the accident happened on June 3rd, 1871.
The following I transcribed from the probate record. Copy is very hard to read. Note: wife is Elizabeth (Turner) Trumbo Morehead. (--- = unable to read)
Camelus Trumbo
To Joseph Brown
Apr 8th, 1869 visit & medicine for wife and child 3.00
Mar 4, “ Prescription & medicine for child 1.00
July 6, “ Visit – medicine for child 3.00
“ 7, “ “ “ 3.00
“ 9, “ “ “ 3.00
“ 16, “ “ “ 3.00
Sept 10 “ Prescription & Medicine for sf. 1.00
“ “ “ wife 1.00
“ 14 Visit & medicine for wife 3.00
Jan 28th, 1870 Visit ---- ------ ------- of son 10.00
Feb 8 “ Prescription & medicine for wife 1.00
Sept 18, “ Visit & medicine for son 2.50
Oct 14, “ Prescription & medicine for son 1.00
April 19th, 1871 Prescription & medicine for son 1.00
May 21, “ “ “ self 1.00
“ 24, “ “ “ 1.00
June 3, “ Visit and med. for sf. 2.50
“ 4, “ “ “ 2.50
“ 5, “ “ “ 2.50
“ 6, “ “ “ 2.50
“ 7, “ “ “ 2.50
$51.00
March 15th 1870. Pd By --- bushels Potatoes
@ ---- per bushel 3.75
------ -- 1871. Pd By 1 gal. coal oil .40 4.15
Bal. Due. 4.15 $46.85