WASHINGTON (USA TODAY) -- The House side of the U.S. Capitol was closed temporarily Thursday for investigation into a possible asbestos release.
During ongoing asbestos abatement work, a potential release affected the House side of the Capitol, officials said. The incident began sometime between 2:30 and 3 a.m., and a hazardous-material response team is on site.
Samples were collected to determine exposure to hazardous materials, and the much of the area was reopened by 9:30 a.m. ET to Congress members and staff. Some areas, including the East Grand Staircase and a third-floor room, remain off limits.
"All other areas of the House side of the Capitol will return to normal operations, including tours," according to a release from the Architect of the Capitol's office, which is investigating the incident with U.S. Capitol Police. Tours of the Capitol visitor center were not affected.
Republican House leaders said they would delay the start of Thursday's session for two hours, starting at noon, because of the accident.
Contributing: The Associated Press