A cable linking two cabins snapped shortly before the deadly funicular crash in Lisbon this week, according to the first investigative report released Saturday.

The report by Portugal's air and rail accident investigations bureau (GPIAAF) said that the cable had passed a visual check hours before the derailment.

"According to the evidence observed so far, the scheduled maintenance plan was up to date, and a scheduled visual inspection had been conducted on the morning of the accident, which detected no anomalies in the vehicles' cable or braking systems," according to the report.

The Gloria funicular — a yellow railway car which travels up and down a steep slope in central Lisbon — swerved off its tracks near Avenida da Liberdade and crashed into a building on Wednesday, leaving 16 people dead and 21 injured.

What else have inspectors found about the Lisbon funicular crash?

Inspectors said the two cabins had traveled not more than about 6 meters (20 feet) when they suddenly lost the balancing force provided by the connecting cable.

According to the initial findings, the accident happened in under 50 seconds.

Upon inspecting the wreckage at the scene, it was "immediately clear that the connecting cable had given way" at the point where it was attached to the cabin at the top of the hill.

The yellow-and-white streetcar that crashed had been in use since 1914.

Two separate investigations underway

There are two separate investigations into the accident: one carried out by the GPIAAF and another by the prosecutors' office.

The GPIAAF underlined in the report that the two investigations are "completely independent and have distinct purposes."

It added that a preliminary report will be published within 45 days.

A final report containing "the established facts, its analysis, conclusions regarding the causes of the accident, and, if applicable, safety recommendations" is expected to be published later.

The GPIAFF also said that if a final report isn't possible within one year, an interim report will be published instead.

Edited by: Dmytro Hubenko