 -- The father of 18-year-old Alyssa Elsman, who was killed when a driver plowed into a crowd in New York's Times Square last week, wrote an emotional letter to his daughter, saying, "I have a hole in my heart that can never be filled."

The framed letter was placed at a memorial near the crash site.

"My world changed when you came into it and it is unexplainable with you leaving it," wrote Thomas Elsman, father of Alyssa Elsman, a tourist from Michigan who was killed last Thursday when a driver sped into a crowd in Times Square. Alyssa Elsman's 13-year-old sister was among the 20 people injured in the crash.

He wrote that his daughter "loved Times Square."

"She would appreciate all your kind words but she would also tell us all to get back up and continue," he added.

Read the full letter here:

"There is no words that can express our gratitude with the outpouring of love and support this city has shown us. Our medical staff, The NYPD and most of all YOU. This impromptu memorial dedicated to our daughter and seeing and talking to many of you has helped me cope with our loss. I have met so many people from different countries, religions, creeds etc......it doesn't matter..you have shown us that when you remove bias..racism..and ignorance..WE ARE ALL ONE... Your condolences have been sincere and taken to heart. Please also remember there are 20 other families affected by this and please keep them in your thoughts too. Alyssa loved this city...she loved Times Square. She would appreciate all your kind words but she would also tell us all to get back up and continue. That's how full of life my daughter was This city and our hearts are scarred, cut to the core, but in true New York City fashion..We will heal..We will prevail..and we will never forget. Alyssa Lynn Elsman... my beautiful 18 year old girl. I look at myself and will never understand how I could ever have made such an angel...Im glad you got your mothers looks..... I don't know anything currently..I always have the answers..but I am blank...I have a hole in my heart that can never be filled. My world changed when you came into it and it is unexplainable with you leaving it. I love you kid. Just no words <3 Love you love you love you.... Dad"

The suspected driver, 26-year-old Richard Rojas, was taken into custody at the scene of the crash after he plowed through pedestrians from 42nd Street to 45th Street. He was arraigned on charges of murder, attempted murder and aggravated vehicular homicide. Rojas was remanded to custody and will next return to court on May 24. He has not yet formally entered a plea. His defense attorney declined to comment.

ABC News' Emilie Richardson contributed to this report.