ROME >> At least four people were killed on Thursday afternoon after a cable car plunged to earth, rolled down a mountainside and broke apart on Monte Faito, south of Naples, Italian officials said.

A fifth person was in critical condition, according to Luca Cari, a national spokesperson for Italy’s firefighters. “These are very ugly situations,” he said in a phone interview.

The cause of the crash was not immediately clear. The nationalities and identifications of four of the victims, described by officials as tourists, were not immediately released. One victim was an employee of EAV, the public transportation company that manages the cable car, officials said.

Nine people became trapped on another cable car that had stalled lower in the valley, near the town of Castellammare di Stabia, because of the crash, Cari said. They were rescued by firefighters who managed to bring them to the ground one by one using harnesses.

Prosecutors in the nearby town of Torre Annunziata, which has judicial oversight over Castellammare di Stabia, have opened an investigation into the crash.

More than 50 firefighters were involved in the rescue operations. Some worked to remove a piece of cable that had fallen on a local railway and onto the roof of a house, according to a statement by the firefighters.

Bad weather conditions made rescue operations difficult “even on foot,” Vincenzo De Luca, the governor of the Campania region, told the national broadcaster, RAI.