A ball cap lies on the ground near the entrance to Canandaigua Motorsports Park the morning after Kevin Ward Jr. was struck and killed by Tony Stewart in a dirt-track race (Jared Wickerham / Getty Images)

As NASCAR prepared for another day of  racing a little over 12 hours after Tony Stewart struck and killed a driver in a race on a dirt track in Canandaigua, N.Y., drivers paused to share their thoughts on Twitter.

Most reached out with sympathetic messages for the family of Kevin Ward Jr., the 20-year-old who died.

Brad Kewlowski cautioned that, while the incident is being investigated, no one has all the answers to what happened yet.