By Lisa Kashinsky

BU News Service

In the moments and hours following the explosions at the 117th Boston Marathon on Monday afternoon that threw Boylston Street into chaos, people who live and work in the surrounding buildings were faced with confusion, disorientation and ultimately, evacuations.

Rebecca Hildreth, 22, a Boston University student, was with friends at her apartment in Avalon at the Prudential, just behind the entrance to the Prudential Center shopping mall on Boylston Street. As soon as her friends, who were watching the race from her 15th-floor window, saw smoke billowing into the street and people pouring out of the food court, they knew they had to run, taking the stairs to get out of the building.

Hildreth doubled back for her cell phone, worried about finding her father, who was working within a block of the finish line.

“I went to try to run to Copley to find my dad but saw people running toward me crying and so terrified,” Hildreth said. “They wouldn’t let anyone go near the blast. A girl who saw both explosions told me what happened and we were both bawling together.”

Unable to get closer to the explosion site, Hildreth said she ran to her parents’ apartment where her mother and young niece were. Her father returned two hours later.

“He said he saw pools of blood and it was chaos,” Hildreth said.

David Marx, 37, a North End resident who works near Copley Square, said he first learned about the explosions through a text from a friend at 3:30 p.m. He was evacuated from his office at 4:55 p.m.

“When I got outside it was eerie because you knew what had already happened, yet things seemed kind of normal for a post-race day – lots of police, ambulances, runners, race volunteers, which is normal for the race,” he said. “But there were lots of stunned looks on faces.”

Marx said he is working remotely today as the Copley Square area remains closed off.

“With all of the people in the area, photos and videos they took, surveillance cameras, there must be some clue or clues that can help the FBI,” he said.