The flock of crows swooped down and started eating the worms on the ground.
Due to shock, the two started killing any crows that get too close to them. Their actions angered the flock which dived down only to bite them. Some would peck their faces while others clawed at the arms and body.
The damage dealt by a crow was negligible but considering that there were dozens of them, it slowly piled up and eventually caused their deaths.
The survivors nearby became dumbfounded at the scene. They couldn't believe that people could die from getting pecked by dozens of crows. Usually, even if you get attacked by crows, you would only be sent to a hospital to make sure that you're okay. Now, the crows that attacked them were the ones who survived a month in this world. It meant that at one point, it fed on something lying on dead on the street. Thus, causing them to mutate.