(CNN)A fiery crash that killed five children on their way to Disney World and a fatal small plane crash in Michigan are just a few of the incidents that have not yet been fully investigated due to the government shutdown.
Hundreds of National Transportation Safety Board workers and thousands of Federal Aviation Administration employees who investigate significant vehicle, plane and rail crashes have been on furlough since the partial federal shutdown began on December 22, leaving new and ongoing investigations on hold.
Three girls and two boys riding in a church van were killed last week when several vehicles collided on the busy Interstate 75 near Gainesville, Florida. A tractor trailer and a car collided with each other and then hit the van, the Florida Highway Patrol said.
The NTSB has looked into similar highway crashes in the past, but it's unclear whether the agency will investigate the crash or when it will do it.
In Michigan, the wreckage of a small plane crash remained untouched for several days before NTSB investigators arrived, CNN affiliate WNEM reported.
The body of the 83-year-old pilot was removed soon after the crash, but sheriff's deputies had to guard the wreckage, Saginaw County Sheriff Bill Federspiel told CNN affiliate WJRT.
NTSB representatives could not be reached for comment. When CNN called the agency's public affairs office on Tuesday, a recorded message indicated that no employees would respond until the shutdown ends.
Ongoing investigations into earlier incidents would also have been put on hold, said Peter Goelz, a former managing director for NTSB who now works as senior vice president for a consulting firm in Washington, DC.
That includes the investigations of last year's New York limo crash that killed 20 people, and the pedestrian bridge collapse in South Florida.
Peter Goelz, a former managing director for NTSB who now works as senior vice president for a consulting firm in Washington, DC, said that if a major incident takes place, the agency would "undoubtedly call people from their forced leave to go back to work."
For most new incidents, Goelz said, investigators will base their initial findings on reports filed by local law enforcement and emergency responders.
"It's not as thorough as it could be," Goelz said.
The agency has also postponed the announcement of its "most wanted list of transportation safety improvements" until February. The event was initially scheduled for Wednesday.
Dozens of NTSB investigations were also delayed in 2013 when the government shut down for 16 days and the agency's employees were out of duty.
During the 2013 shutdown, there were 59 aviation incidents and other events, including a deadly motorcoach crash, a significant pipeline leak and a house explosion caused by a natural gas leak. The agency only launched investigations into two of them when "it was determined that there was an imminent threat to life or property," the NTSB said at the time.
