(KRON) -- San Francisco 49ers star left tackle Trent Williams' newborn son passed away last week, his wife Sondra announced on Instagram. Trenton O'Brien Williams Jr. died on the night of Nov. 24. Trenton was born prematurely as Sondra gave birth to her son after 35 weeks of pregnancy. According to Sondra, the couple's firstborn and only son was four pounds and eight ounces at birth. He died at the hospital shortly after Sondra gave birth. Golden State Valkyries unveil season games, home opener "It’s been extremely hard trying to process the saddest Hello and Goodbye that I’ve ever had to endure," Sondra's social media post read in part. "Trenton O’Brien Williams Jr., my sweet baby boy, we love you our Forever Angel!" Trenton is the second child to pass away during Sondra's pregnancy. The mother said his twin died early in the pregnancy. 49ers fans went on Trent Williams' Instagram page to send their condolences in the comments section of his latest post. Trent, the 49ers' All-Pro offensive lineman, missed the team's last two games against the Bills and Packers. According to the 49ers' official injury report, he missed Sunday's game in Buffalo due to an ankle injury. Head coach Kyle Shanahan was asked about the tragedy in a news conference Monday afternoon. He said Trent Williams took some time off last week. "He did a little bit of that last week," Shanahan said. "Something that happened that last week and he was there at the hospital with her and got to meet him and say bye. And then he had to cremate him on Friday, so he's been dealing with that and he's working through it. But we're all just trying to be here for him through it all." Christian McCaffrey’s season ‘potentially’ over after knee injury in 49ers’ loss to Bills The tragic passing of Williams' son marks the second 49ers player this season to lose their child this season. Cornerback Charvarius Ward announced the death of his toddler daughter in October.