A bridge that was intended to last for 100 years collapsed in Huidong, Guangdong province, on Monday night, after only 30 years of use.

The incident has sparked questions over the quality of its construction, with some locals suspecting it was a jerry-built project.

“Why has a bridge that was designed to be used for a century collapsed after it has been standing for only 30 years?” a resident surnamed Huang was quoted as saying in Southern Metropolis Daily.

The bridge was constructed in 1983, and should have been able to withstand the normal loads of motorized traffic.

However, local authorities attributed the collapse to several vehicles crossing it that they say were overloaded.

At least four overloaded vehicles crossed the bridge before it collapsed on Monday, authorities said.

A van fell into the lake below when the bridge collapsed at about 9:30 pm. The driver and a passenger climbed out of the van's windows and were rescued by people on the shore.

A further investigation has also been launched to discover the causes of the collapse.