Nick Berg was a big-hearted risk-taker - intent on making the world a better place, willing to do the heavy lifting to make that happen and daring enough to go almost anywhere to do it.

As his body arrived at Dover Air Force Base in Delaware yesterday, friends and co-workers recalled Berg, 26, as a good-natured, adventurous young man whose solo journey to war-torn Iraq was not exclusively for monetary gain.

That assessment was echoed by the White House: "Nick Berg wanted to build a free Iraq for the Iraqi people ... He was an innocent civilian seeking to help," spokesman Scott McClellan said.

President Bush also addressed the videotaped and Internet-posted beheading of Berg for the first time since his body was discovered Saturday near an overpass in Mosul in northern Iraq.

"Their intention is to shake our will. ... Yet by their actions they remind us of how desperately parts of the world need free societies. ... We will complete our mission," he said.

A fuller picture of the suburban Philadelphia businessman - a backer of Bush and a supporter of the war - emerged yesterday, with the release of e-mails that he had written during the first of his two trips to Iraq, one of which describes a damaged radio tower at Abu Ghraib prison.

Berg's father, a retired schoolteacher who opposes the war and sports an anti-Bush bumper sticker on his car, said in an interview with the Associated Press that U.S. officials are responsible for the abuse of Iraqi detainees at Abu Ghraib that led - according to the executioners - to his son's death.

"Nick died for the sins of the Bush administration," Michael Berg said.

Dozens of news media vehicles were outside the Berg's split-level home in West Chester, Pa., yesterday, where a funeral director visited the family.

A private memorial service for Berg - limited to friends and family - is scheduled tomorrow afternoon, said Carl Goldstein, of Goldsteins' Rosenberg's Raphael-Sacks funeral home. "The family is very happy Nick is back in the United States," he said.

Berg, who operated a small communications company from his family's home, first went to Baghdad in late December, returning Feb. 1. In March, he returned to Iraq, but after having trouble finding work there, he told his parents that he would be home by the end of the month.

Detained in Mosul

On March 24, he was detained by Iraqi police in Mosul in a late night sweep. He was released on April 6 after his parents filed alawsuit in federal court in Philadelphia, contending that the U.S. military was illegally holding him.

U.S. officials say he was never in the custody of coalition forces. While in Iraqi police custody, they said, he was interviewed three times by FBI agents who were suspicious of his identity and warned that the country was too dangerous for unprotected Americans. He was offered a free flight home, but he declined, officials said.

But Hugo Infante, a Chilean reporter who got to know Berg in Baghdad, told Newsday that Berg recounted that Iraqi police had quickly handed him to U.S authorities in Mosul and that he had been held the entire time in a jail where U.S. soldiers were his guards.

Berg contacted his parents April 9, but he was not heard from again.

U.S. troops discovered his decapitated body Saturday.

A video posted Tuesday on a Web site linked to al-Qaida depicted the beheading by a group that said it was avenging the abuse of Iraqi prisoners by American soldiers.

'An adventurous sort'