“ryan and zeek, my heart is so heavy right now. I can’t put into words how grateful I am for every second I was lucky enough to spend with you,” Gerber wrote alongside a series of photos with the pair on Tuesday. “The two people who made me smile the biggest. I will never forget that. I can still feel you here. I can still hear your laughs.”

She continued, “I promise to keep trying to smile for you, I love you both forever. ❤️ rest peacefully always by each other’s side.”

Breaux, 18, and Bishop, 20, died when their car crashed into a tree and went up in flames around 1:40 a.m. on Sunday in Thousand Oaks, California. They were both pronounced dead at the scene.

Gerber’s mother, supermodel Cindy Crawford commented with three prayer hand emojis, while Meadow Walker, whose father, Paul Walker, also died in a car accident wrote, “Love you sweet Kaia,” with three heart emojis.