PHILADELPHIA (AP) — The driver of a tractor-trailer that overturned, sparking a blaze underneath a major Philadelphia interstate that resulted in the collapse of an overpass, failed to slow down on the exit ramp, federal investigators said.

The National Transportation Safety Board issued its final report in the June 2023 crash at an Interstate 95 exit ramp and “found probable cause” that the driver, who was killed, exited the highway above the posted speed limit, and possible fatigue played a role in the incident. There were no other deaths or injuries.

Another factor in the intense blaze that collapsed part of the highway was the driver’s failure to secure a manhole cover on the truck, which was transporting about 8,500 gallons of gasoline.

The NTSB’s findings come after state officials had said earlier that the driver lost control of the vehicle on the exit ramp. Federal officials had earlier flagged the open manhole cover as an issue as well.

Interstate 95 reopened less than two weeks after the collapse, a quicker-than-expected rebuild to get traffic flowing again on a heavily traveled stretch of the East Coast’s main north-south highway.

Among the “lessons learned” the NTSB cited in its report were the importance of mitigating commercial truck driver fatigue and the benefit of electronic stability control, a system designed to prevent rollovers. The truck did not have the system, investigators said, but it could have stopped the rollover even with the truck traveling over the posted speed limit.

The report is dated March 19, but the NTSB publicized it Thursday.