LOL! But seriously, I didn't know that hurricanes can "kill" other hurricanes. Has this happened before?
Yes, the shear associated with a hurricane can affect weaker ones, and can even absorb it. A perfect example was in 2005 when Tropical Storm Alpha was absorbed by Wilma.
The outflow from one storm can mess up the other storm as it causes extra wind shear on the other one. They're both trying to compete for warm water, inflow of air at the surface, and clear venting at the top for outflow.
Tropical Storm Fiona has winds of 60 mph now, and it's turning northward towards Bermuda but will slowly weaken as it heads out to sea afterward.