From Boston.com's Jackie Reiss and Matt Rocheleau in Kenmore Square:
In the aftermath of the Boston Marathon explosions, runners and spectators in the Kenmore Square area reacted with shock as police and other personnel tried to bring order to the chaos.
Marathoner Maggie Blanchard, 39, said she had been looking forward to finishing her final mile when another runner stopped her near the intersection of Massachusetts and Commonwealth avenues and told her the race was over.
Blanchard, wrapped in a garbage bag to keep warm Monday afternoon, distractedly looked east as she said that she hadn't gotten in touch with her father yet, who was waiting for her near the finish line.
After using a passerby's phone and leaving yet another frantic message for her father, Blanchard hurriedly headed toward the MBTA bus parked a few steps away.
Runner Paige Scofield, 26, said she knew something was wrong when she saw other marathoners begin to slow and come to a stop.
"Everyone was just standing around," she said. "When I heard, I was terrified. My fiancé was supposed to be waiting for me at the the finish line."
Luckily, her fiance Francisco Contijoch, 26, was underground at the Hynes station when police began evacuating him.
"I couldn't walk anywhere," he said. "I tried looking for her."
The couple described a frantic waiting period where they couldn't get in touch - Contijoch's phone had died, and Scofield didn't run with her phone - until they spotted each other near commonwealth and Massachusetts Avenues.
"We were lucky," Contijoch said.
A school bus shuttled Boston police down Commonwealth ave near Massachusetts Avenue Monday afternoon. At the corner of Massachusetts and Commonwealth avenues, police used megaphones to tell passersby to evacuate the area.
"There have been some explosions. Please evacuate the area," police said on the megaphones. "We're looking for secondary devices."
Runners were directed to take MBTA buses to Boston Common.
Between the Kenmore and Copley square areas, hundreds of people used their cell phones to try to reach loved ones. Many said they were having trouble sending messages and making calls.
Arielle Valdez, a 21-year-old senior at Boston University, said she and her friends were walking toward the Boston Marathon finish line when they heard news that explosions had gone off there.
Valdez said she and her friends were near the corner of Commonwealth and Massachusetts avenue just a few blocks away from the finish line and might have been closer to, or at, Copley Square had they not made several unplanned stops to watch the race.
"It's something you wouldn't expect during the Boston Marathon," she said, sniffling and wiping tears from her cheeks.
"It's not a time for anything like this," she added. "We were here to support the runners but not through a time of grief. This is messed up."
Valdez and her friends, Molly Harrison and Yelena Shuster, both 21-year-old seniors at BU, stayed in the area amid the chaos, handing out their own supplies of water, food and offering cell phones for runners and spectators desperately trying to reach loved ones.
"It's the most scary thing - especially because no one has [cellular] service," said Valdez.
Moments after news outlets sent out alerts and after the news hit social media, some runners continued along the route through Kenmore Square unaware of what had happened.
Others slowed and stopped as they checked cell phones.