The final moments of Rachel Corrie, the American peace activist crushed to death beneath a pile of earth and rubble in the path of an advancing Israeli army bulldozer, were described to an Israeli court by an eyewitness yesterday.

The parents of the 23-year-old, who was killed by the bulldozer in March 2003, were present to hear the harrowing account on the first day of hearings in a civil lawsuit they have brought against the state of Israel. The country has never acknowledged culpability over Ms Corrie's death.

Richard Purssell, a British activist with the pro-Palestinian International Solidarity Movement (ISM), said he watched in horror as Ms Corrie was dragged four metres by the bulldozer moving forward at a "fast walking pace".

He told how her fluorescent orange jacket became invisible beneath a pile of earth churned up by the blade of the 56-tonne D9 Caterpillar machine. Mr Purssell explained that he and two other ISM volunteers had been summoned from the Rafah neighbourhood of Tel Sultan earlier in the day to help five activists prevent bulldozers from carrying out what they feared would be the demolition of Palestinian homes. The five, including Ms Corrie, were in the suburb of Hai Salaam, close to the border with Egypt.

Mr Purssell said the incident took place about 20 metres from the house of Dr Samir Nasrallah, a pharmacist well known to ISM activists, who often place themselves between Israeli forces and Palestinians to try to stop the Israeli military from carrying out operations. Ms Corrie climbed on to the earth mound being created in front of the bulldozer, with her feet just below the top of the pile.

"She is looking into the cab of the bulldozer," Mr Purssell recounted. "The bulldozer continues to move forward. Rachel turns to begin coming back down the slope ... As she nears the bottom of the pile, something happened to cause her to fall forward. The bull- dozer continues to move forward and Rachel disappeared from view. The bulldozer moves forward approximately another four metres before it stops." Mr Purssell, who works as a landscape gardener in the UK, said that before the bulldozer came to a stop, other activists started running towards her – as he himself did a few seconds later.

"I heard a lot of people shouting and gesturing to the bulldozer to stop," he told the court, adding that the bulldozer then "reversed back in the tracks it had made, in a straight line; Rachel is lying on the earth".

He said three ISM activists – Alice Coy, Greg Shnabel and Will Hewitt – rushed to adminster first aid. "They began to support her neck," he added. "They were holding her. She was still breathing. I did not get involved because I am not first aid trained." He insisted "everything that could be done was done" by the volunteers. Ms Corrie died of her injuries soon afterwards.

Asked in cross-examination by the state's attorney why Ms Corrie acted as she did by standing in front of the bulldozer, Mr Purssell said he did not know but could only speculate that "she didn't want the bulldozer to go any nearer Dr Samir's home".

Ms Corrie's parents, Craig and Cindy, from Olympia in Washington state, have brought their civil action in part to challenge the military's account of their daughter's death. Israel claims its troops were not to blame and the bulldozer driver did not see her or run her over deliberately, even though witnesses insist she was clearly visible.

Within weeks of her death, the Israel Defence Forces accused Ms Corrie and the ISM of behaviour that was "illegal irresponsible and dangerous". In 2004, Lawrence Wilkerson, an aide to the then US Secretary of State, Colin Powell, wrote to the Corries saying Israel had failed to carry out the "thorough, credible, and transparent" investigation promised at the time by Israel's Prime Minister, Ariel Sharon.

The Corries' attorney, Hussein Abu Hussein, claimed before the hearing began that the troops "acted in violation of both Israeli and international law prohibiting the targeting of civilians, and the disproportionate use of force against non-violent protest with blatant disregard to human lives".

Mr Corrie said the family had been seeking justice for seven years. "I think when the truth comes out about Rachel, the truth will not wound Israel, the truth is the start of making us heal."

His wife said they were still waiting for an open investigation. "I just want to say to Rachel that our family is here today trying to just do right by her, and I hope she will be very proud of the effort we are making," she added.