BOSTON — A Massachusetts woman is safe after she and a friend escaped from a ferry that sank off the coast of the East African nation of Tanzania, killing at least 31 people, her parents said Thursday.

Hilary Strasburger of Somerville called her parents at their Maine vacation home and told them she and another American were on the top deck of MV Skagit when strong winds sank it Wednesday. More than 100 passengers are still missing.

The Red Cross said at least 146 people were rescued after the accident. The MV Skagit left Tanzania’s commercial capital of Dar es Salaam on Wednesday en route to the main island of Zanzibar, a semiautonomous region that is a popular tourist destination.

Strasburger, 26, used a borrowed phone to call her parents in their Jackman, Maine, vacation home and told them that she and a friend were not injured after escaping from the sinking ferry, her mother, Carrie Strasburger, told The Associated Press.

“She was on the top level of the ferry inside and she felt the boat tip over and tried to go out a door but she couldn’t get it open, I think she said there was too much water pressure, and someone pushed out a window and she and her friend climbed out the window and were in the water,” Strasburger said. “And I don’t know how long she was in the water … she managed to get to a life raft where she and her friend were in the life raft for two hours and a rescue boat came.”

Strasburger had recently finished her graduate studies at Lesley University and, before she started working in Marlborough in September, she wanted to go back to Uganda for a month to visit with the children in an orphanage she previously worked in. She met a friend in the East African nation and had just arrived in neighboring Tanzania for a brief holiday when the accident occurred, her mother said.

Strasburger said the victims included women and children who could not get out of the ferry as it sank.

She received an initial medical examination in Zanzibar and was then flown to Dar es Salaam. U.S. embassy officials arranged for her to receive replacements for medicine she had lost. She was expected to fly to Uganda on Friday, where she will decide whether she wants to continue with her monthlong trip, her mother said.

“I know that what she went through is gonna be difficult for her to process, with, y’know, the time that she spent in the life boat, what she witnessed and heard and listened to. She said to us she’s still processing what had happened,” Carrie Strasburger said.

“The one bag that kept with her through the whole thing had her passport and her visa … in it, and a little bit of money. She said she was very fortunate,” Strasburger said. “Our thoughts and prayers are with the people who are getting very different phone calls than we got and have lost family members.”

Last September, more than 200 people were killed when a crowded ferry traveling between two islands of Zanzibar sank.