Many moons ago, I worked in a building that was next to a truck garage. On a hot summer day, a truck limped in full of animal entrails. One of its axles broke and the contents of the truck spilled all over the place, just in front of our entrance. In the sun. It was only cleaned up after several hours and the smell lingered in our office building for literal months, as the air circulation in this building was almost non-existent.

The smell itself was comparable to a very strong blood smell with a metallic, copper-like undertone.