Mark Memmott

Both the former IRS commissioner who was in charge when the agency singled out some conservative groups for extra scrutiny and the man who replaced him will be appearing at a Senate Finance Committee hearing Tuesday morning.

Douglas Shulman, an appointee of President George W. Bush who left the IRS last November, and acting commissioner Steven Miller (who is losing his job because of the scandal) are due at the 10 a.m. ET hearing.

(We're following the news from Oklahoma, where a tornado devastated the Oklahoma City suburb of Moore on Monday. Most recent update: 10:10 a.m. ET.)

While the number of deaths and amount of damage caused by a huge tornado that tore through Moore, Okla., on Monday remain high, state officials announced just after 9 a.m. ET Tuesday that fewer people than feared may have lost their lives.

The Internal Revenue Service is under fire for improperly singling out some conservative groups for extra scrutiny — putting them through months (or longer) of questions that delayed or derailed the organizations' requests for tax-exempt status.

Well, now the chairman and ranking Republican on the Senate Finance Committee have some questions and requests — actually dozens of them — for the IRS.

ABC News White House correspondent Jonathan Karl now says he regrets that some key parts of a major story he reported on May 10 were wrong.