Officer's have blood stripes. It's not b/c they died in general. It's b/c NCO's, SNCO's and officers fought so hard at the battle of Chapoltapec that we added the blood stripe to show thanks to all their courage and leadership.
a ton of Pvt/PFC's also died there but it was to show their leadership above all else.
If I remember right Cpl/Sgt's blood stripe is 1" wide, SNCO's are 1.25" wide 2ed LT - Capt is 1.5 and Maj up is 2" wide.