Family and friends bid farewell in a tearful memorial service dedicated to four international Penn State students who died in two separate car accidents during spring break.

Graduate students Djung Yune Tchoi, 33, Hyeonhwa Lee, 30, and Joo-Ook Kim, 27, died in a car accident on March 5 on Interstate 80, near Danville.

The students were travelling to New York, when the car Tchoi was driving crossed into traffic.

Chen-Ying Chien, 20, died March 7 in a car accident along the Florida Turnpike.

Chien was on vacation in Florida with friends, and she was traveling to Miami when her car struck a concrete barrier.

More than 150 family and friends gathered at Pasquerilla Spiritual Center to remember the students through speeches and slideshow presentations of each of the students.

Yeonsoo Kim, a friend of Tchoi, tearfully remembered how she enjoyed struggling with difficult problems as a doctoral student in mass communications.

"I still can't grasp the reality of her absence. I don't know how to say goodbye to her," she said.

"I love my friend and I really miss her," Kim added.

Tchoi's co-adviser, Ronald Bettig, read a letter of recommendation that he would have written for her, if given the opportunity.

"She is a brilliant scholar as well as a kind and committed citizen," he said. "She wanted to help create a world where everyone had a chance to succeed."

Sook-Young Park said she remembered meeting Lee through the church services on campus.

"She used to sing so passionately, which left an impression on me," Park said.

"She was like an angel sent by God," she added.

Lee was always gentle and helpful to other students, said her co-adviser, Suet-Ling Pong.

"Hyeonhwa was reliable, conscientious and hard working," she said.

"She was the kind of student every teacher adores ... we love her so very much," Pong said.

Yoo-Bok Kim, Joo-Ook Kim's father, choked up as he spoke through a translator and asked the audience to keep his daughter in their memories.

"When you live in happiness, Joo-Ook will be there with you," he said.

Soyeon Cho, a friend of Joo-Ook Kim, said she was optimistic and had a great sense of humor. "Joo-Ook had the heart of an angel," she said.

"'Don't cry because it's over, smile because it happened' ... that is how I feel about Joo-Ook's friendship."

Charles Smith, Joo-Ook Kim's adviser, said she was a "brilliant student" and a "precious person."

"Joo-Ook, my friend, I am ever so happy our paths crossed ... you lightened the lives [and] brought joy to the lives of those you met. I shall remember you forever," he said.

Chien was described as having an "adventurous heart" by her roommate, Alice Chen.

"I feel very lucky to have had her as a roommate. She was one of the most special people I knew," Chen said.

Chen read her final farewell to her friend, Chien, recalling their spring break trip to Florida.

"We will always remember watching the fireworks together at Epcot, the last night we were together," she said.

"We will never forget how you always made us laugh. We love you and you will always remain in our hearts."