As the inquiry into Queensland’s worst ever floods begins in Brisbane today, the families of those killed by the extreme flash flooding in Toowoomba and the Lockyer Valley are still severely traumatised by their experiences. The $15 million inquiry will examine the disaster, government preparedness and the emergency response.

When investigators move to Toowoomba and the Lockyer Valley, where 23 people died and six are still missing, they will hear the most gruelling accounts of how life and death were moments apart. Hundreds of people who have survived came very close to joining the list of dead and missing.

The inquiry will also hear evidence from people who predicted the disaster and are devastated that vulnerable adults and children in the path of the floods were given no effective warning of its deadly force.

They claim that top-priority Bureau of Meteorology severe weather warnings issued at 5am and 11am on January 10 for “heavy rainfall leading to localised flash flooding” that could potentially worsen the existing flood situation, did not convey the danger or the scale of the disaster. Low-lying streets in Toowoomba CBD and Grantham are frequently submerged during heavy storms.

But an online weather forum of meteorologists and storm chasers grew increasingly anxious as they watched radar images of a large storm cell they saw moving cross the coast heading south-west across towards the Lockyer Valley and Toowoomba on January 10.

A weather watcher posted to the forum at one minute after midday that the extremely unstable moisture-laden air “could well be a recipe for some very heavy flash flooding-type storms to pop up at any time…”. Ominously, at 12.16pm, meteorologist Anthony Cornelius posted to the forum that Sandy Creek in Grantham had caught a few people by surprise over recent days and he hoped they were prepared, but noted “sadly I think most won’t know until the water starts lapping up at their homes due to our insufficient warning system”.

Another weather-watch forum member posted at 1.10pm:

“Anthony, do you think the [Bureau of Meteorology] is on the case with that [storm] cell. If not you probably know who should be told about it. Those rain rates between Esk, Crows Nest and Toowoomba are truly frightening. I fear that there could be a dangerous flash flood very soon particularly in Grantham. Am I overreacting?”

Five minutes later, at Murphy’s Creek, two women in a car were washed off a causeway. One of their rescuers phoned police at 1.20pm seeking help but the phone lines were already so overloaded he could not get through. He went himself with a friend to brave the torrent and rescued the women.

Meanwhile on the weather forum, Dave replied at 1.22pm:

“No, you’re not overacting Neil!! We’ve just been chatting about it here.”

Adam then reported at 1.41pm the disaster unfolding in Toowoomba as well as in the Lockyer Valley below the Range:

“It has absolutely bucketed down in the last 30 minutes in Toowoomba. I wouldn’t be surprised if we got 50mm. Keep a close eye on the Lockyer Creek at Helidon and now Cressbrook Creek. There will be a wall of water coming down it.”

Weather forum member Buster was becoming very anxious that a warning should be given as he posted at 1.42pm:

“Dave, I live in an area that is equally not used to being so saturated and equally not used to falls of that nature. I just know that 56mm in an hour here would produce a flood of frightening proportions and one likely to put lives at risk. Falls higher than this in the immediate area are likely. I repeat my question . . . Does someone in Esk, Grantham, Toogoolawah need to know what’s possible. Who do we tell?”

Dave posted at 1.49pm:

“There is nothing really that we can do is there? This is why I wanted to see some sort of heads up for everyone in South East Queensland a few days ago, because it is hard to justify sounding the SEWS (Emergency weather siren) just for that part of Lockyer Creek (for example) if they have no telemetry telling them just yet that there is a huge wall of water coming down the creek in that area.”

On the eastern edge of Toowoomba, resident Denise Reeves was watching the downpour when she saw three mains drains at the headwaters of East Creek suddenly burst, sending huge water fountains gushing four metres in the air. Knowing the wall of water created would be deadly by the time it travelled 2km towards the centre of the city, she ran to the phone and tried desperately to reach Toowoomba City Council.

She dialled three times but could not get through. She then dialled the local newspaper and still could not get through. Critical minutes had passed.

“At the pace it was travelling it would have been in town by then,” she said. “Short of driving down there and screaming for people to get out of the way, there was nothing I could do.”

The wall of water reached James Street, the main street carrying traffic across the city. It was at the intersection of James Street and East Creek that Toowoomba mother Donna Rice and her sons Jordan, 13, and Blake, 10, were among dozens of people who were suddenly hit by a front of water three metres deep coursing down the creek.

Rice phoned 000 several times from her car and eventually got through. Meanwhile, by-standers tried to rescue them.

Blake was carried to safety and a rope was thrown to Donna Rice and Jordan but it broke and the two floated away, grabbing desperately to a signpost. When Jordan was pulled from the signpost by the force of the current, his mother also let go, apparently trying to save her son whom she knew was very scared of water.

The two were swept away to their deaths. Rice’s husband John Tyson is too distressed to even consider addressing the inquiry.

Reeves said the sad fact is flash flooding down East and West Creeks has happened many times before in ordinary storms because the creeks are inadequate to drain storm rain: “We are amazed more people weren’t killed on the roads that day.”

Meanwhile, in the centre of the CBD, West Creek broke its banks, lifting cars, vans and shipping containers down the creek like toys and carrying them away. Vision of the destruction was broadcast worldwide but no one at this location died.

Police, swift water rescue crews and by-standers waded into the furore to rescue people who had been swept away or who were clinging to signposts or trees. The water from the Toowoomba flood flowed west towards Oakey.

Meanwhile, along the escarpment, the torrential rain poured 700m down the mountainside, gathering pace and force as it went until it was sweeping people and furniture from homes, picking up cars like toys and ripping houses from their foundations. Amazingly, no one on the Range highway or in Withcott was killed, but at Murphy’s Creek a couple was swept from their house to their deaths, along with another father and daughter.

About 5km down the creek the flooded mountain gullies flowing down from Toowoomba joined Murphy’s Creek to form Lockyer Creek at Postman’s Ridge, picking up houses and slamming them against trees. By 3.30pm the river at Lockyer Creek at Helidon shot up from four metres to 13 and broke the river gauge.

The Bureau of Meteorology rain gauge records at Lockyer Creek

This is where James and Jenny Perry and their son Teddy were lifted off the Warrego Highway in their car and carried along Lockyer Creek. What is more arresting than the death of James Perry is that a QFRS Special Operations rescue team was already on location, also trapped by the flood, and managed to commandeer a media helicopter and save Jenny Perry and swim with her to safety.

Even the special operations QFRS crew had no heads-up that the weather that day would be anything out of the ordinary. Fortunately they had packed their swift water rescue gear and urban rescue equipment and a weatherproof radio which they used to call for a rescue helicopter equipped with a winch. It was this team which found and rescued Teddy Perry and another 28 people at Grantham, who were clinging to their gutters in the torrent or had scrambled onto their roofs.

At 3.45pm when the 13-metre wall of water had flowed east to hit Grantham, there had still been no official warning for people living in the Lockyer Valley of the impending disaster. It was this wall of water that tore through Grantham and resulted in the highest death toll of the floods, destroying almost all of the town.

Matthew Keep and his wife Stacy lost both of their mothers and their daughter Jessica, 23 months. Stacy’s mother Dawn Radke, 56, has still not been found. The bodies of Pauline Magner, 65, and Jessica were found.

Matthew Keep was airlifted to safety by the rescue helicopter. Amazingly, two of their children, 5-year-old Madison and 4-year-old Jacob, survived the flood in their home. Their cousins, university students Brad and Natasha Long, tried to outrun the tsunami but were both lifted off the road as they fled.

They believe the lack of warning caused the deaths in their family and in the town. “If there had been warning many of the people who died, would not have died. No one needed to die. No one should have died,” Long said.

The Bureau of Meteorology issued a flood warning for moderate to severe flooding in Lockyer Creek at 4.16pm. It upgraded to a top priority flash flood warning at 5pm, to be broadcast with the SEWS emergency weather siren, warning of the extreme rises in Lockyer Creek with very fast and dangerous rises possible downstream at Gatton.

The emergency warning siren had been sounded at least three and a half hours after witnesses reported the unfolding disaster. A weather forum member commented: “About freakin time!!! FINALLY!!!”

Brad Long is still traumatised by the split-second decision he made at his uncle’s house to run back up the road to help his wife instead of going into Matthew and Stacy Keep’s house where the three lives were lost.

“Why didn’t I run inside? It still haunts me every minute of every day to think that I could have gone in there and saved the people who died,” he said. “I don’t know what I could have done. It’s something that’s going to haunt me for the rest of my life.”

As well as moving the township to higher ground, Long would like to see improvements to the 000 system and weather warnings. He is not alone.