The mystery behind the Amtrak derailment in Philadelphia deepened Wednesday as feds said the train’s engineer wasn’t on his cellphone before the crash.

The National Transportation Safety Board studied train operator Brandon Bostian’s phone data, and Amtrak’s Wi-Fi system records.

“Analysis of the phone records does not indicate that any calls, texts, or data usage occurred during the time the engineer was operating the train,” the NTSB said in a statement.

Eight people were killed in the May 12 crash.