In what is unbearably sad news, the 4-year-old son of Raiders defensive line coach Terrell Williams died Friday after acquiring “a sudden and unexpected illness earlier this month,” according to the team.

Tyson Williams had just celebrated his fourth birthday on Nov. 1 when he got sick. He battled with the sickness for a week before dying at Oakland Children’s Hospital.

“We were all shocked by the news we received when we arrived in Baltimore last night,” coach Dennis Allen said in a statement. “Terrell and Tifini have been dealing with unimaginable tragedy this week, and our hearts go out to them. We’re all deeply saddened by the passing of Tyson, and our deepest sympathies go out to Terrell and his entire family.”

More from the team release:

Born in West Lafayette, Ind., on the day his dad’s Purdue team beat Michigan in Ann Arbor, Nov. 1, 2008, Tyson in four short years had made countless friends in Indiana, Texas and California. He loved cartoons, and his family especially was proud of how caring he was to his eight-month-old brother, Tahj. In fact, before Tyson passed away, he taught his brother to clap.

The Williams family appreciates its privacy during this extremely difficult time. The family will hold a private memorial service this week.

Allen said the defensive coaching staff will share the workload in Williams’ absence, and Williams will have as much time as he needs to mourn with his family before returning to the team.

To send condolences to Williams, mail them to the Raiders headquarters at 1220 Harbor Bay Parkway/Alameda, CA 94502.

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