Investigators are seeking cellphone records for the drivers involved in a fatal shuttle-bus crash near Seattle-Tacoma International Airport in July as they try to determine the collision’s cause, according to a preliminary report issued Tuesday.

The collision occurred on International Boulevard just north of South 176th Street about 1 p.m. on July 25. Officials believe a shuttle bus from the Seattle Airport Marriott was heading north when a car heading south crossed a raised median and hit the bus, flipping it onto its side. One shuttle passenger was killed.

The crash is being investigated by the National Transportation Safety Board (NTSB), the King County Sheriff’s Office and the Federal Motor Carrier Safety Administration. A preliminary report from the NTSB published Tuesday offered few new details. The agency said it is reviewing its requirements for vehicles operating as private commercial transportation, while the sheriff’s office has requested the cellphone records to see if distraction played a role in the crash.

The shuttle bus is operated by Town Park based in Pennsylvania, according to the report. The driver had a commercial driver’s license, even though it was not required to operate the shuttle. The shuttle was equipped with seat belts, which the driver was wearing at the time of the crash, although none of the passengers were, according to the report.

The car’s driver, a 45-year-old woman, was also wearing a seat belt.

One shuttle passenger, 45-year-old Bryan R. Panzanaro of New York, was partially ejected and killed in the crash. Both drivers and the shuttle’s seven other passengers were injured.

Panzanaro and three of the injured shuttle passengers were leaders at ABM Aviation, which provides services to airlines and airports, according to an ABM Industries spokeswoman.

The King County Sheriff’s Office, which is investigating the collision, asked the public last month to contact it with information.