I saw a what I would call a vibrational disturbance into the future

While walking on a bridge I saw everything vibrating around me maybe 20 feet in every direction. At first I thought it might have been an earth quake but after looking closer I noticed that the bridge wasn't actually moving at all but it looked like the hand railing was vibrating soo fast that it was impossible. It was just like when you strike a guitar string and it vibrates soo fast that you can see straight through it. After 2 weeks or so I passed that exact same spot and saw someone had placed a cross on that same spot for a loved one that had jumped off the bridge at that exact same spot. Can anyone help me to understand this.