"I can't put the two opposites of the day together. Most of day spent running through the streets where people were cheering and waving. People were lined up to give us water and one woman was giving us tissues, another popsicles. They were giving their day to cheer us on in such a wonderful way and I was feeling 'wow, humanity is wonderful' and then after the bombing, 'wow, someone made that choice,'" said Kate Williams of Waitsfield, who completed her first Boston Marathon on Monday.

Williams and her brother ran the race; both completed it and were uninjured, but not unshaken, by the bombing.

"It was a great day. The weather was perfect. The fans were amazing and then the bombs," she said.

Her brother had finished ahead of her. They reconnected when Williams got done, with a time of 3:36. She ran the Burlington Marathon last year to qualify for Boston.

"We were fighting our way to the subway and heard the explosions. A volunteer near us said it was construction, but an MBTA security guy asked us to let him know if we saw anything suspicious," she said.

The subway system wasn't operating at full capacity and Williams and her brother kept working their way towards the subway line that would get them home.

"Two blocks away people were getting their legs blown off and we were just trying to find a subway to get home. We got to China Town and had to walk over to Charles. We were hobbling – we'd just finished a marathon. Everyone was on their phones and sharing information about the bombs," she said.

"I feel like I have a new appreciation for the surreal quality of disasters," she added.

"We weren't really afraid, but right towards the end we had the very intense sense of 'let's get the heck out of the city.' We were able to let our families know that we were alright and we knew they were alright," she said.

Williams and her brother got a train at Charles and were able to get to their cars and headed to their parents' house in Belmont.

"My parents and my brother's kids had been at the finish line. It's hard to process the randomness of it. We were one family doing what so many others had been doing and we were fine," she said.

Williams had intended to spend the night at her parents, but after dinner she yielded to her great desire to get home, cranked up some loud music and returned to her husband and children in Vermont.

She said she told her kids pretty much everything about the race and the event and said that she expected it would sink in a little slowly.

"It's hard to comprehend that I happened to finish at the time I finished. Other people finished later and they had a bomb go off. It seems very random. And to bomb at an event like that so goes against the nature of that event that it really hurts," Williams said on Tuesday evening, April 16, seated on the couch with her 13-year-old daughter next to her.