AFAIK, there has only been one deadly incident in all the time these programs have been going on, and that was back in the 40s.
It was a USN P2V, callsign
Snowcloud Five, lost Sept. 26, 1955 while flying a penetration on hurricane "Janet". Its last transmission was:
"NAVY RECONNAISSANCE FLIGHT 5U93, OBSERVATION NUMBER FIVE, AT 1330 GMT (8:30AM EST), MONDAY, LOCATED AT LATITUDE 15.4 DEGREES N, LONGITUDE 78.2 DEGREES W. OBLIQUE AND HORIZONTAL VISIBILITY 3-10 MILES, ALTITUDE 700 FEET, FLIGHT WIND 050 DEGREES (NE) 45 KNOTS (52 MPH). PRESENT WEATHER LIGHT INTERMITTENT SHOWERS, PAST WEATHER SAME, OVERCAST AND SOME SCUD BELOW, SURFACE PRESSURE 1,003 MILLIBARS (29.62 INCHES), SURFACE WINDS 050 DEGREES (NE), 45 KNOTS (52 MPH). BEGINNING PENETRATION."
Eleven souls on board, all lost, the aircraft was never found.