10.55am: “Did they find him yet?” One man said, pulling up in his ute.

“Excuse me love, is there anything I can do to help?” A woman from down the road asked SES workers.

As the search for 11-year-old Ryan Teasdale stretched on into Friday morning, residents from the surrounding Unanderra streets pulled up to Riley Park at regular intervals.

Like the emergency crews, they were baffled over how a child could simply disappear while playing with his friends.

Along with SES, police rescue crews, paramedics and council workers, Wollongong Lord Mayor Gordon Bradbery paced across the parks soggy ground.

“As I understand it, and I’m only hearing what many others have heard, that the children were making use of the opportunity on boogie boards to come down this wonderful slope [at Riley Park],” Cr Bradbery said.

“But, unfortunately in flooded circumstances ... people, not only children but adults, enter floodwaters. Here’s a circumstance that reinforces the message; don’t enter floodwaters.”

Councillor Bradbery said council engineers were on scene to assist the SES.

10:47am: A diver has been called in and is checking drains in the area.

UPDATE: The search for 11-year-old Ryan Teasdale continued at first light on Friday.

Dozens of searchers from the State Emergency Service, Police, Marine Police NSW Ambulance and NSW Fire and Rescue are on scene at Riley Park continuing to search for the boy who went missing while bodyboarding with friends on Thursday night.

Wollongong City Council staff are also on site as they have detailed knowledge of the drain network in the area.

“Staff are providing information and access to the drainage system,” a council spokesman said.

“Council have also brought in one of their contractors who is using a camera to inspect parts of the system that are not easily accessible.”

State Emergency Services personnel are conducting searches of the drains in the area surrounding the park.

Other SES crew and council staff are also going door-to-door in streets around the park to try and access other drains.

At a press conference on Friday morning Lake Illawarra police commander Superintendent Zoran Dzevlan said more than 100 emergency services personnel were on the scene.

“We’ve been searching that immediate vicinity [around Riley Park] and we’ve also been searching where the drains finish into the creeks around the area,” Supt Dzevlan said.

He said police believed Ryan “may have fallen into one of those drains”.

Residents are still shocked about the incident and are confused as to how it could have happened.

They said the floodwaters were fast-flowing in the park at the time of Ryan’s disappearance.

Ryan went missing on Thursday night and was presumed to have been swept away in flood waters at Unanderra following an afternoon of fierce rainfall that caused chaos across the region.

He was last seen riding a boogie board at flooded Riley Park off Central Avenue with his brother and a group of children on Thursday afternoon.

Police said the brother left the park about 4.30pm when he could not find Ryan, but soon discovered he was not at home either.

Ryan’s family began searching for him, before raising the alarm at 6.30pm when he could not be located.

State Emergency Service crews rushed to the scene and immediately began their search, aided by police and specialist ambulance crews trained in swift water rescue.

Distraught onlookers watched on as the operation unfolded.

As at 8pm police were focused on stormwater drains in the vicinity of the park, with emergency service personnel using headlamps to light the way. 

One woman took to social media to say the park often became a popular sliding ground during heavy rainfall. 

“We saw them, about 20 kids with their boogie boards, it's something kids do there all the time. So devastating,” she wrote.

A resident at the scene, who did not wish to be named, told the Mercury: “they bring their body boards and race down the hill”.

“I hope this young boy is okay.”

Ryan was last seen wearing a blue board shorts, no shirt, and was in possession of a blue body board which has not been located. 

Anyone with information on his whereabouts is asked to contact police immediately. 

Meantime, SES crews were kept busy throughout the evening as dozens of drivers became trapped in flood waters.

Two elderly people were helped out of a car stuck in waters on Taylor Road at Albion Park. The couple was uninjured and the car will remain in position until flood waters subside. 

At 8pm, emergency services received reports six or seven cars were trapped on Macquarie Pass between two sections of fast-running water cascading down the mountain. It is understood authorities were concerned part of the mountain might give way.  

SES crews from Wingecarribee were able to access the area and walked out nine people who had been trapped in the cars.