Dozens of investigations by the National Transportation Safety Board (NTSB) are on hold during the partial government shutdown, as nearly the entire staff is furloughed. One investigation surrounds a fiery crash in Florida this month that claimed the lives of seven people, including five children. It was the deadliest accident the NTSB has not been able to investigate.

CBS News obtained documents that show the shutdown has prevented the NTSB from launching 74 accident investigations, including probes of 12 plane crashes that have killed 18 people. One is a small plane crash in Beaver Island, Michigan, that killed the pilot, and another in Sioux Falls, South Dakota, that killed two.

Of the 397 employees at the NTSB, just 26 were deemed essential to "manage the shutdown." In order to recall more investigators, there has to be a reasonable likelihood of an imminent life-threatening safety issue.

Of the 74 missed investigations, at least 20 cases were deadly, resulting in 34 deaths and 18 injuries in the air, on the water, and on the roads.

Just five investigators have been recalled, including four to work on Lion Air 610's voice recorder. Sources worry the shutdown is causing the board to miss opportunities to prevent future accidents that will cost more lives.