After a fatal bus crash Tuesday in Virginia—at least the fourth such commercial bus accident in three months—federal regulators immediately issued an order to shut down the company that was responsible. Four people died in the accident and more than 50 were sent to the hospital. But as it turns out, regulators had just days earlier passed up a chance to take the Sky Express bus company off the roads.

According to report in USA Today, five days before the fatal bus accident in Virginia on Tuesday, the Transportation Department’s Federal Motor Carrier Safety Administration made a crucial decision: It could have ordered a shutdown of Sky Express based on the company's history of accidents and driving violations, but instead chose to put it off.

After yesterday's crash, regulators shut down the company on the same day—an action that was possible because the agency had proposed shutting the company down back in April after reviewing the company’s safety record. Under agency rules, the Federal Motor Carrier Safety Administration can’t shut down bus companies immediately, a Transportation Department spokeswoman explained to USA Today:

[Transportation Department spokeswoman Candice] Tolliver said the agency could not shut down Sky Express immediately because it must wait 45 days from when it proposes a shutdown. After 45 days — on May 27 — instead of shutting down Sky Express, the agency decided to probe new safety concerns, she said. "We took the option of extending the investigation by 10 days (from May 27) to further investigate the carrier," Tolliver said. "We wanted to make sure we had an air-tight case to shut the company down completely."

That extended investigation was apparently cut short when the accident occurred. The discount bus company is now under an indefinite ban. (Sky Express said in a statement that it was the "first serious accident" involving its buses. The Associated Press reported that the company offered condolences to the victims and said it would cooperate with an investigation by the National Transportation Safety Board.)

On the same day that the Federal Motor Carrier Safety Administration decided to postpone shutting down Sky Express, it issued a press release touting the more than 3,000 surprise passenger bus inspections it conducted in a two-week period in May.

“The public deserves safe passenger bus transportation every ride,” said FMCSA Administrator Anne Ferro, as quoted in the release. “FMCSA and its law enforcement partners will not rest until we weed out every unsafe passenger carrier and driver.”

The agency last month announced new rules aimed at improving the safety of passenger buses, including raising testing standards for bus drivers seeking commercial driver's licenses. It also proposed requiring a full safety audit before bus companies are allowed to operate.

As an earlier report by USA Today noted, full safety audits are more comprehensive and more costly than roadside inspections, and hundreds of motor coach companies have never undergone these audits at all.