Two Montreal taxi passengers had a close call Wednesday afternoon when a large metal construction beam struck the car they were in, smashing the rear window.

The seven-metre beam fell from the construction site of the city's new French superhospital. It landed on the cab, near the corner of Viger and Sanguinet streets.

Two women, who were sitting in the back seat of the cab, escaped without injury.

But the pair, visiting from Ottawa, said they were outraged by the actions of the cab driver, who they say overcharged them and sped away from the scene shortly after being filmed by a Radio-Canada crew that happened to be in the area.

The construction consortium that runs the site says the beam was being lifted by a crane when it hit the structure. It slipped and fell, bouncing off the ground and striking the taxi.

"We are making our internal inquiry right now to establish what were the causes of the incident," said Marc Verreault of Consortium Pommerleau-Verreault.

Quebec's workplace health and safety board is investigating the incident.