The Senate Homeland Security Committee and Senate Rules Committee will hold a joint hearing on Feb. 23 on the security failures that led to the breach of the Capitol by pro-Trump rioters on Jan. 6, the panels announced Tuesday.

Details: The committees have invited former U.S. Capitol Police chief Steven Sund, former House Sergeant at Arms Paul Irving, former Senate Sergeant at Arms Michael Stenger and D.C. Metropolitan Police Chief Robert Contee to testify. Sund, Irving and Stenger all resigned in the wake of the riots.

Why it matters: The hearing will likely be the tip of the iceberg when it comes to congressional investigations into the insurrection, which resulted in former President Trump's second impeachment and eventual acquittal in the Senate on Saturday.

• House Speaker Nancy Pelosi on Monday said there will be an independent, 9/11-style commission set up to investigate the attack.
• House Homeland Security Committee chairman Bennie Thompson (D-Miss.) sued Trump in federal court on Tuesday, accusing the former president and far-right groups of conspiring to incite a riot with the goal of preventing Congress from certifying the 2020 election.