The 26-year-old actress - who played his on-screen sister in Marvel blockbuster 'Black Panther' - has opened up following her late co-star's tragic death after he died on Friday (28.08.20) aged 43 after a long battle with cancer.
In a video of her heartbreaking spoken word piece on Instagram, Letitia began: ''It is written, there is nothing new under the sun. But the sun stood still that morning, refusing to shine.
''Dark clouds surrounding, confusion setting in, tears flowing, rivers so deep. I didn't know this is what I was waking up to, my brother, an angel on earth, departed.
''A soul so beautiful, when you walked into a room, there was calm. You always moved with grace and ease. Every time I saw you, the world would be a better place.
''Words can't describe how I feel, how we all feel, that losing you was forced upon us, to accept this as a new reality. I wish I got to say goodbye.''
Letitia referenced Chadwick's secret battle with cancer, as the late star had continued to work and film while recovering from surgeries and undergoing chemotherapy.
She continued: ''I messaged you a couple times, but I thought you were just busy. I didn't know you were dealing with so much.
''But against all the odds, you remained focused on fulfilling your purpose with the time handed to you. And I'll never forget the day that I met you, before I got on the plane to L.A. for my first meeting with you.
''God told me that you were my brother and that I am to love you as such, and I always did, and I always will. But now, my heart is broken.
''Searching for old message of exchange, cards filled with your handwriting and memories of you holding my hand as if it was for eternity.''
Letitia admitted she thought they ''had more time'' as friends and co-stars, and she added she is ''trusting God to heal all wounds''.
She concluded: ''I thought we had more time, and many more years to come, for more laughter and for more moments of me picking on you on set. Leaning my head on your shoulders in the front room, as Ryan gave us notes.
''I thought this would be forever, this hurts. I'm trusting God to heal all wounds. It is also written that all things are made new, there is light in the darkness.
''Streams of living water flow, giving new life. And all that's left now is for us to allow all the seeds that you have planted on the earth to grow, to blossom, to become even more beautiful.
''You're forever in my heart.''
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