Two people were seriously injured in crashes in the Western Bay of Plenty in the weekend.

The first serious crash was at Pongakawa and the other on SH29 near The Lakes roundabout.

An 18-your-old was flown by rescue helicopter to Rotorua and then Waikato Hospital on Saturday, after suffering serious injuries in the Pongakawa accident.

Western Bay of Plenty road policing manager Senior Sergeant Ian Campion says the injured person came out of a moving vehicle in Maniatutu Road at about 1pm.

The details of how he came to fall from the vehicle in which he was a passenger are unclear at this stage, says Ian.

In the second serious crash, a pedestrian suffered serious leg injuries when he was struck by a runaway trailer about mid-day Sunday.

The man was beside SH29 when a trailer detached from a vehicle that had exited the roundabout and was heading towards Cambridge Road.

'Investigations are underway to establish how the trailer detached,” says Ian.

On Saturday morning, city-bound traffic over the Tauranga Harbour Bridge was disrupted after a red utility struck the steel crash barrier.

The driver was not injured, but the crash caused significant traffic hold-ups because oil on the roadway meant police were unable to immediately clear the lane, says Ian.

Another crash was reported on SH29, Lower Kaimai area, around 11.30pm on Sunday.

The road was blocked for a couple of hours after a truck jack-knifed.

Ian says a heavy motor vehicle was towing another that had broken down when the brakes on the towed vehicle failed.

'It jack-knifed the towing vehicle and blocked the highway.”

Broken glass being cleaned up at the aquatic centre in Pyes Pa this morning. Photos: Cameron Avery.

Other reports are coming in of a car crashing through the front door of the Liz van Welie Aquatics Centre in Pyes Pa.

Police had no details of this incident and a reporter at the scene says there wasn't much to see this morning.

A caller to the 0800 SUNLIVE news hotline reported the incident to SunLive.