I know nothing about Luke or what caused his death. However, in general, young athletes passing away suddenly from a not-clearly-apparent cause is sometimes hypertrophic cardiomyopathy. My mother has this condition and I have done significant research on this topic. I encourage all people with children or young adults entering the space of competitive sports to have their heart checked by a cardiologist. A simple 20-minute cardiac ultrasound can be the difference between life and death for some athletes.
For all those with the expendable income to do so, I encourage you to set-up an automatic monthly donation to a charity that you believe in. It is much better than donating a random jersey number amount every once in a while when someone you do not know passes away. It allows the charity to better budget for the year when they have auto-donations coming in. For example, I auto-donate to Feeding America every month, as I believe no child should ever be hungry, regardless of their situation.