The helicopter pilot was talking to an air traffic controller at the time of the deadly Houston crash

Houston– When the plane disappeared, the helicopter pilot was talking to an air traffic controller in Houston hit the radio towerAccording to a preliminary report from the National Transportation Safety Board, all four people on board died.

The report said pilot Samantha Grandbouche contacted a controller after taking off on Oct. 20 to tour the area and was told minutes later to maintain visual separation from another helicopter in the area.

“The pilot was reading instructions when the radio transmission abruptly ended,” the report said. “No further communications have been received from the accident helicopter.”

The helicopter struck a 1,003-foot-tall (306 m) radio tower about 100 feet from its top and exploded as both the helicopter and tower fell to the ground along with pieces of the helicopter, including the fuselage, embedded in the tower, the report said .

Grandbouche died in the crash along with passengers Marie Alonso, her ex-husband Julio “Cesar” Lerma and their school-age son Dylon Lerma.

The report shows that the surveillance footage showed two of the tower’s three beacons flashing, but the third one was not visible.

The tower’s owner, SBA Communications, told investigators there were no outages.

The company did not immediately return a message seeking comment to The Associated Press on Friday.

SBA Communications previously said it was cooperating with investigators and had issued a notice to flight missions advising pilots of potential threats in flight, but declined to comment further, citing the ongoing investigation.

The NTSB report shows that the notice was filed on October 16, after the company acquired the tower in September.

The preliminary report does not provide a probable cause for the crash, which will appear in a final report expected in 18 to 24 months.