Dasep Habibi can't talk about last month's tsunami without breaking down.

Key points: At least 430 people were killed when the tsunami smashed into the coast on the Sunda Strait, between the islands of Java and Sumatra

At least 430 people were killed when the tsunami smashed into the coast on the Sunda Strait, between the islands of Java and Sumatra The Anak Krakatau volcano is still erupting violently almost every day

The Anak Krakatau volcano is still erupting violently almost every day Reports of new cracks have added to fears of another volcanic landslide, like the one that caused the tsunami

The 31-year-old and his wife managed to run to higher ground at Sumur on Java's south-west coast. But they lost their two small children, Muhammad Fajrul, 3, and Kaila, 22 days old.

"My wife saw the massive wave but I was asleep," he said.

"I tried to grab the kids but I could only find their pillows.

"When I went back later — even though I had injured my foot — I was so sure they would be dead, there was no doubt."

The family's home was washed away, along with their main source of income: Mr Habibi's auto workshop.

The couple are among thousands of Indonesians now living in displacement camps after the tsunami devastated Java's west coast on December 22.

Concrete slabs are sometimes all that is left in Sumur after the tsunami hit. ( ABC News: Anne Barker )

Sumur was one of the places worst hit, but blocked roads and debris made it difficult to get into the town until last week.

The devastation is horrific.

Homes had their roofs shorn off or walls washed out. Boats are half sunk in the ocean. Many were snapped in half by the powerful waves.

But it's what you don't see — as much as what remains at Sumur — that shocks the most.

Along the main coastal road, the seafront appears bare. Suddenly you realise the concrete slabs in the ground were rows of houses that lined the shore.

A squat toilet in each is all that remained after everything else was carried inland.

All around, families and neighbours huddle together with little to do.

Some have begun preparatory work to rebuild their homes, undeterred by the threat of another tsunami.

Others will need months — or money they don't have — to rebuild their lives.

Sumur was one of the worst places hit. ( ABC News: Anne Barker )

One woman, Munarsih, lost her home when it literally filled with water.

She almost drowned in her own living room.

Munarsih's house collapsed after the tsunami. ( ABC News: Phil Hemingway )

"The water got into the room and I couldn't get out. I could hardly breathe. The water was already up to here," she said, indicating her neck.

"My 13-year-old grandson kicked something so it would open. After that I tried to find a way out.

"I was yelling for help but no one came. I kept yelling but no one replied. I found out there was no one else there.

"I kept trying to find a way out of the room but it was so hard the place was full of water and debris."

The water level slowly fell and Munarsih was saved. But the house had collapsed.

The tsunami flatted homes, but has also affected the tourism industry. ( ABC News: Anne Barker )

Efforts to rebuild homes could be premature, with fears still running high of another tsunami.

The Anak Krakatau volcano is still erupting violently almost every day. Columns of ash and smoke have reached heights of 1,500 metres in the past week.

Reports of new cracks have added to fears of another volcanic landslide, like the one that caused the tsunami.

It's not only residents who fear a second tsunami.

Domestic tourism is a major industry along Java's coast.

Hotels are often full this time of year. But many have reported mass cancellations by tourists who are now too frightened to visit.

At least 430 people were killed when the tsunami hit. ( ABC News: Anne Barker )

The Aston Hotel at Anyer has lost about 80 per cent of its guests. Manager Doddy Fathurahman said it could be six months to a year before business recovered.

"People are afraid of the tsunami, the first tsunami's effect is quite high, and now people are afraid of the second tsunami."

Some tourists have come just specifically to see the volcano in action.

Rerta Prasetya travelled by train for 24 hours from eastern Java with a friend to take photos and see Anak Krakatau from the beach. But even he is taking precautions.

"I asked for the room upstairs," he laughed.

"I'm a little nervous. That's why last night we requested room at the top floor."