updated 04/15/2013 AT 7:00 PM ET
•originally published 04/15/2013 AT 4:45 PM ET
In the chaos after the deadly explosions that rocked the Boston Marathon finish line, runners and eye witnesses took to social media to share their experiences.
Jeff Chin, 27, of Boston gave his first-person account of watching the terror unfold to PEOPLE’s Steve Helling:
I was near the Apple Store, heading to the Dunkin Donuts when I heard it. I was maybe a block away from it, and it was really loud, like a lightning strike had hit really close. And then I heard another one.
People started screaming. I saw a guy with his shirt off, and it was wrapped around his hand and it was soaked red with blood, but I don’t think he had lost it. I didn’t look too closely.