Jennifer Lawrence helped a woman who had collapsed in Santa Monica yesterday.

The 21-year-old actress - who is best known for playing Katniss Everdeen in The Hunger Games - went to the aid of a young woman who had collapsed outside of the star's home in the exclusive Los Angeles suburb, and stayed with her until police officers arrived.

"Lawrence was walking her dog when she saw the juvenile. She stood by as a Good Samaritan until officers arrived and spoke with them. It was a couple of juveniles involved in the incident. It could have been alcohol related. She's okay," said Sgt. Richard Lewis of the Santa Monica Police.

Jennifer was seen helping the young lady with her belongings. However, she was thought to be very concerned for her well-being during the incident.

"Jennifer ran outside her apartment when she heard a girl scream and immediately called 911. When the EMT arrived, she stayed to make sure everything was okay. She was really scared for the girl," an onlooker said. The incident was resolved at the scene and the girl was taken home by a friend.