Tom, a carpenter from Colorado, made headlines after spending six months building his daughter the impossible: a treehouse she could access with her wheelchair.

Sophie, 9, was born with muscular dystrophy and had never been able to climb like the other kids. So her dad got creative—designing a sturdy ramp, an elevator pulley system, and wide decks with railings.

When he posted the final reveal on social media, the video went viral. Millions were moved to tears.

“I just wanted her to feel included,” Tom said, holding back tears. “Now she says it’s her castle in the sky.”