By David Shepardson

WASHINGTON The House of Representatives Oversight Committee said on Tuesday it is investigating the U.S. Transportation Department's response to a series of aviation and rail safety issues.

Republicans on the panel in a letter to Transportation Secretary Pete Buttigieg said the committee was conducting oversight of the department's response to near-miss aviation incidents and train derailments. They also said they were seeking "a briefing, documents and communications related to the department's efforts to investigate and remediate these issues to protect the safety of all Americans."

The Transportation Department did not immediately respond to a request for comment.

The letter, signed by committee chair James Comer and other committee Republicans, cited unresolved safety recommendations made by the department's Office of Inspector General.

"These safety failures have eroded the public's confidence in air and rail safety and necessitates thorough investigation," the lawmakers wrote in the letter.

The National Transportation Safety Board (NTSB) is investigating seven near-miss runway events since January. In March, Buttigieg said a series of aviation close calls was "deeply troubling and deserve our immediate attention."

The Federal Aviation Administration (FAA) and NTSB last month said they were investigating an Aug. 11 near collision between a Southwest Airlines Boeing 737 and a Cessna Citation 560X business jet in San Diego that were about 100 feet (30 meters) apart.

The FAA has been without a permanent administrator since April 2022. President Joe Biden's nominee to head the agency withdrew in March and the White House has yet to announce a new nominee.

The issue of rail safety has drawn renewed attention since the Feb. 3 derailment of a Norfolk Southern train in East Palestine, Ohio, that caught fire and released more than a million gallons of hazardous materials and pollutants.

The Republican letter seeks all communications between the Transportation Department and the White House related to a number of transportation events including the East Palestine derailment and a Feb. 4 near-miss incident in Austin, Texas in which a FedEx cargo plane and a Southwest Airlines Boeing 737 came within about 115 feet (35 meters) of each other.

The Senate Commerce Committee in May approved rail safety legislation that tightens rules on trains carrying flammable substances. The measure has not been taken up by the House or the full Senate.

(Reporting by David Shepardson; editing by Timothy Gardner)