WASHINGTON (NewsNation Now) — Slain U.S. Capitol Police Officer Brian Sicknick was honored Wednesday in the building he died defending.

Colleagues and members of Congress paid their respects while Sicknick lay in honor at the Capitol, ahead of a ceremonial departure to Arlington National Cemetery.

Sicknick, 42, died after sustaining injuries during the siege of the U.S. Capitol on Jan. 6. The U.S. Capitol Police said in a statement that Sicknick was injured “while physically engaging with protesters,” though the cause of his death has not been determined.

During the turmoil on Jan. 6, Sicknick was hit in the head with a fire extinguisher while protecting those trapped in the Capitol. Sicknick, an Iraq War veteran, returned to his division office after the incident and collapsed, according to Capitol Police. The next day, he died from his injuries.

President Joe Biden traveled to the Capitol to pay tribute to Sicknick shortly after the viewing began Tuesday night, briefly placing his hand on the urn in the center of the Capitol Rotunda, saying a prayer and sadly shaking his head as he observed a memorial wreath nearby. He was accompanied by first lady Jill Biden. House Speaker Nancy Pelosi, Senate Majority Leader Chuck Schumer and a handful of other congressional leaders also paid their respects.

Vice President Kamala Harris and her husband, Doug Emhoff, paid their respects Wednesday, placing their hands over their hearts and then touching the urn.

A steady stream of lawmakers and police officers made its way through the Rotunda. Michigan Rep. Dan Kildee, one of several Democrats who were caught in the upper gallery of the House chamber while the rioters banged on the doors, wiped away tears.

Because of the coronavirus pandemic, the ceremonies will be open to invited guests only.

Sicknick is only the fifth person to lie in honor in the Capitol Rotunda, a designation for those who are not elected officials, judges or military leaders. The others who have lain in honor were John Gibson and Jacob Chestnut, Jr., two officers who were killed in a 1998 shooting at the Capitol; civil rights leader Rosa Parks, who died in 2005; and the Rev. Billy Graham, who died in 2018.

Sicknick, from South River, New Jersey, enlisted in the National Guard six months after graduating high school in 1997, deploying to Saudi Arabia and then Kyrgyzstan. He joined the U.S. Capitol Police in 2008.

House Speaker Nancy Pelosi and Senate Majority Leader Chuck Schumer announced in a statement Friday that Sicknick would lie in honor.

In their joint statement, Pelosi and Schumer said: “On behalf of the House of Representatives and the Senate, it is our great privilege to pay tribute to Officer Sicknick with this lying-in-honor ceremony. May this ceremony and the knowledge that so many mourn with and pray for them be a comfort to Officer Sicknick’s family during this sad time.”

Sicknick’s family released a statement Saturday, thanking the congressional leadership:

“The family of U.S. Capitol Police Officer Brian D. Sicknick thanks the Congressional leadership for bestowing this historic honor on our fallen American hero. We also wish to express our appreciation to the millions of people who have offered their support and sympathies during this difficult time. Knowing our personal tragedy and loss is shared by our nation brings hope for healing.”

FAMILY OF OFFICER BRIAN SICKNICK