Whenever you are attaching to a house you need to seal against moisture.
Porches meeting masonry are a particularly important since masonry transmits moisture. This porch was obviously built about 50+ years ago so back then they made the brick ties very large. Normally a 3/4" or 1" bolt.
This kind of thing is the result of a few factors. Often it happens after years of leaking flashings melt the beam to the point that it will no longer support snow load or even itself.
The other half of the equation, the footings may have been slightly too small to do the job, when snow load is factored in when soil gets moist during freeze, or thaw or just a rainy fall or spring the inadequate footings will get pushed into the ground levering the porch from it's connection.