The B24 killed 15,000 in training missions alone during WWII. These were state side losses, not combat.
The losses weren't the fault of the aircraft. It was a fine aircraft, and a well built, well designed one. I've got several years' experience in them. They're forgiving, easy to fly (heavy on the controls), relatively simple, straight forward aircraft.
Crews weren't afraid of them. They tended to prefer them to the B17. They were more survivable, carried more, and were better in most respects. The Liberator and Privateer had their drawbacks, but flying qualities wansn't one of the. The big, high-lift Davis wing flew like a charm, and it was controllable right into the stall. It flew like a big four engine cub.
The original wet wings did tend to leak, especially with the mass production and reduced attention that could be devoted to properly keeping them sealed. Avgas leaking down the dihedral of the wing tended to concentrate in the bomb bay area, and these vapors could be ignited. I've had the cat walk and bomb bay full of avgas, before.
The B24 had glass sight gauges for the fuel; tall affairs about three feet high posted next to the bomb bay; damage those and there's a big fuel leak. The hydraulic tank of H5606 was in the flight deck area, as was the aux hydraulic pump, fuel selectors, rotary inverters, batteries, master relays, APU, etc. Everything flammable and every ignition source came together on the flight deck, which was a disadvantage. I've put out two flight deck fires using my nomex jacket before.
Turbo Commanders have had a bit of a problem with their empennages (losing them inflight). The C-119 had a habit of losing wings if roll input was used aggressively under a load. The AT-802 gets squirrely if the tailwheel isn't locked on landing. None of those things made them poor designs; they had limitations that needed some respect. The C-130 can experience rudder reversal in flight, but it's not easy to do. Again, it's a known thing. The B24 has no ground steering: it's differential brakes, or nothing. It won't roll straight more than a few feet; the nosewheel is free castering and canted forward, and even a small rock on the ramp will cause it to turn. It made for an interesting landing with hydraulics out. Again, not a poor design, just a characteristic of which one ought to be aware.
When the tow truck delivered my '84 SDV to the dealer with a blown head gasket, the service manager seemed very impressed I'd gotten 80,000 miles out of it. 
