A construction worker was killed and four cars damaged when a slab of concrete fell from an under-construction expressway on Sunday afternoon.

According to an Expressway Authority of Thailand (Exat) statement, the bars holding a lifting frame snapped, causing a section of concrete to fall down onto Rama 2 highway.

Exat initially reported the falling slab damaged four cars and obstructed traffic on both sides of the highway. It said the contractor was contacting the damaged parties about compensation.

However, media reports said one construction worker was killed, with no other details.

Dashboard cam footage from a car showed a large concrete slab falling about 4.30pm onto the road island, crushing a worker and damaging four cars.

The driver said he heard a noise above him and then a huge concrete slab tilted and fell down.

Another motorist said he had to swerve violently to avoid being hit by the falling concrete. His vehicle suffered a cracked windshield and a punctured tyre.

The construction of the expressway over Rama 2 highway has had several previous accidents.

On the night of July 31, 2022, a five-tonne, 10-metre-long concrete beam fell off the U-turn bridge and dropped onto a car, killing two people and injuring five others.