When there is a catastrophe or perceived danger, it is part of our human design to seek each other out for support and comfort. This is because a group can combine resources, defend each other and survive far more effectively then a person can individually. Physical proximity and touch cause us to secrete happy-chemicals that relax and calm us during times of threat and stress.
The old War of The Worlds radio hoax is the classical example in social psychology. When people heard over the radio live, that aliens were attacking earth and killing people, the phone lines lit up with people calling to talk loved ones. Hordes of people walked, droved and cycled to be with one and other. People gathered in groups holding hands, hugging and generally being close to each other around the radio. They didn’t realize it was just a well produced radio drama.