Natasha Richardson's son pays tribute to her on 15th anniversary of her death

Natasha Richardson's son is remembering his mom 15 years after her tragic death.

The actress, best known for her role in 1998's "The Parent Trap," died in 2009 at the age of 45 from an epidural hematoma due to a blunt impact to the head from a ski accident.

"15 years since you've left this plane onto forever more," Daniel Neeson, Richardson's son with husband Liam Neeson, wrote Monday in an Instagram tribute.

"I look forward to re uniting one day but for now I take solace in knowing you're beside me every step of the way," he added. "Hopefully, I'm making you proud."

Daniel Neeson said his aunt, "Nip/Tuck" actress Joely Richardson, recently told him "that we sometimes forget that we're on an ever spinning planet."

"Change is inevitable, and we must embrace it with open arms," he continued. "If you're a believer or not in quantum physics, the past, future and present coexist. We're all interconnected here and over there through love. The greatest life force. Choose it above all else."

Richardson -- the daughter of Tony Richardson and Vanessa Redgrave -- and Liam Neeson were married from 1994 until her untimely death, and shared two sons, Daniel and Micheál Neeson.