A Tesla driver killed in a Silicon Valley crash was playing a video game on his smartphone at the time of his fatal crash, investigators said on Tuesday. The National Transport and Safety Board (NTSB) investigation found that Walter Huang, a 38-year-old Apple software engineer and game developer, made no attempts to stop his vehicle as it sped towards a crash barrier before the 2018 crash. Huang's Tesla Model X was in "Autopilot" mode and traveling at about 70 miles per hour when it crashed into a safety barrier and was struck by two other vehicles. He died in hospital from his injuries. "If you own a car with partial automation, do you not own a self-driving car. So don't pretend that you do," said the NTSB chairman, Robert Sumwalt.