Two men are seriously ill in hospital after being hit by a delivery van as they were changing a wheel on a highway in Tuen Mun early yesterday.
The accident prompted a warning from police to motorists not to attempt repairs on busy roads, but to wait for a tow truck.
Driver Lo Chun-yip, 40, who was flung more than 10 metres by the impact, was in serious condition in Tuen Mun Hospital, while his 40-year-old passenger and employee, identified as Ng, was in critical condition.
Police said Lo stopped his car in the slow lane of the Yuen Long Highway near Fu Tei at 5.30am to change the back right wheel after the tyre burst.
"As they were trying to remove the wheel, they were hit by the delivery van, which also slammed into the car," a police officer said. He said Lo and Ng were knocked unconscious and Ng also suffered serious injuries to his head, body and legs.
Police are investigating whether he was crushed between the two vehicles. The van driver was unhurt and he passed a breath-alcohol test.
Police have reminded motorists not to change a wheel or try to repair a broken-down vehicle on highways.
They should switch on the hazard warning lights and leave the car and the carriageway if it was safe to do so.
Drivers should not attempt repairs but wait for a tow truck or rescue vehicle.
Police figures show 66 people died in 65 traffic accidents in the first seven months of this year.