Was there no intel that they were headed straight to death?

Quite the opposite. Operation Neptune, the maritime landings, and the wider Operation Overlord were meticulously planned to an exhaustively thorough extent by Allied high command. The Cotentin Peninsula was chosen as a destination because it didn't mean heading "straight to death". German strategy was largely predicated on the allies launching their invasion via the Pas de Calais, where the Channel is only some 35km across. This would be where the crossing would be quickest, reinforcement would be easiest and air cover could be most total, and so naturally this is where German defences were most heavily concentrated. The Cotentin Peninsula offered a number of highly suitable landing beaches, but was considered logistically unsuitable by the Germans and as such was far less heavily defended and garrisoned. Allied intelligence went to considerable lengths in the build-up to Operation Overlord to fool the Germans into believing that the landings were indeed going to occur near Calais, including leaking false invasion plans, building artificial airfields and even inflatable armoured divisions, which kept a considerable proportion of the German forces in France tied up there.

Vast amounts of planning went into the landings. Beach defences were reconnoitred in extensive detail, with each bunker, wire line, ramp, and gun position known. Each unit going ashore was briefed to a high detail about their landing sector, and their specific objectives on hitting the beach. Considerable planning went into nullifying threats to the landings. Aside from naval and aerial bombardment, the large-scale parachute drops carried out by the British 6th Airborne Division (known as Operation Tonga) and the American 82nd and 101st Airborne Divisions were planned to eliminate coastal artillery batteries and German support positions, and to capture crucial bridges and road junctions to prevent German reinforcements reaching the beach head. Operation Deadstick, for example, saw 'D' Company, 2nd Battalion Ox & Bucks Light Infantry capture 'Pegasus' Bridge over the River Orne near Ranville, and thus successfully prevent the 21st Panzer Division from counter-attacking the British beach head at Sword Beach.

The vast array of heavily customised armoured units known collectively as "Hobart's Funnies" after Major General Percy Hobart of the 79th Armoured Division were also designed to specifically deal with threats on the landing beaches and inshore. Sherman duplex-drive or 'DD' tanks were designed to 'swim' inshore and provide immediate fire support to landing infantry without requiring heavier landing craft; other Shermans were fitted with 'crab' flails designed to clear paths through minefields blocking paths inshore. The heavily armoured Churchill tank was fitted with a variety of adaptations. The Churchill 'Crocodile' replaced its hull machine gun with a flamethrower to clear emplaced positions such as fox holes; the Assault Vehicle Royal Engineers - AVRE - was fitted with an enormous 290mm petard mortar, known affectionately as the 'flying dustbin' designed to reduce bunkers and fortifications to rubble. You can see its frankly awesome firepower in this archive footage. AVREs were also designed to carry fascines - vast wicker bundles - to bridge ditches and allow tanks to climb off the beach without needing to use the likely mined and emplaced slipways.

Did we technically win that battle?

Operation Overlord was a major success. While it didn't meet its ultimate objectives on the first day - the capture of Bayeux, Caen or St Lo, the beach head was achieved with a fraction of the casualties planned for by Allied Command. By the 7th of June, 160,000 men had come ashore. The beach heads were linked by the 12th of June, and as British forces drew German armoured forces into the battle for Caen, American forces broke out to liberate most of the Cotentin Peninsula by July.