State Police are hunting for the man who sexually assaulted a 24-year-old woman in Cambridge on Memorial Drive early Tuesday morning.
Police are hoping video from nearby security cameras may have caught some of the attack or the perpetrator, said State Police spokesman David Procopio. With the attacker still at large, some women in Cambridge said they are feeling on edge, compelled to be more cautious at night.
The victim was approached by a man on a bicycle while she was walking toward the river from a Cambridge bar at 2 a.m. She tried to escape, but was physically and sexually assaulted near the Weld Boat House, police said.
Her screams for help caught the attention of two witnesses, who ran toward her, causing the attacker to get on his bike and flee.
The woman, a Boston resident, was taken to St. Elizabeth's Medical Center and has since been released, according to police.
“She did the right thing by screaming for help,” Procopio said. “That alerted the good Samaritans to her distress and prompted them to rush toward her, interrupting the attack.”
That sort of quick action from two strangers should be commended, said Stephanie Trilling, a community awareness and prevention services manager at the Boston Area Rape Crisis Center.
“It’s an incredible story that people heard and ran over to help and the person left as a result,” she said. “We all have a role to play.”
She said that type of response and awareness is what she teaches in sexual assault prevention classes.
Police described the attacker as a white man in his late 20s to early 30s with a stocky build and blond or light brown hair.
Honey Holman, 18, was reading on the grass on Tuesday afternoon just across the street from the site of the assault, not far from Harvard University’s campus.
She recently moved from Jackson, Miss., to start her freshman year at Harvard.
“That’s just terrifying,” she said, adding that she had viewed Cambridge as safer than her hometown.
Harvard e-mailed an advisory to its students about the assault, reminding them to walk in groups, especially at night. Procopio said using “the buddy system” in urban areas at night is generally recommended.
Holman said she would make sure she wasn’t alone at night. “I hate that I have to think that way,” she said.
State Police, who have jurisdiction over the river and the river roads on each side, respond to a handful of assaults or attempted assaults along the Esplanade each year, Procopio said. But he could not recall another recent incident on the Cambridge side.
Christie Reed, 40, a Cambridge resident running near the boathouse Wednesday afternoon, said she considered the area safe.
“I was just telling a friend, when I walk home at 1 a.m., I never feel unsafe,” she said.
“But I feel like this can happen any place,” she said of sexual assault.
Anyone with information about the incident or the assailant can call State Police at 617-740-7875.
Sara DiNatale can be reached at sara.dinatale@globe.com. Follow her on Twitter @sara_dinatale.