Houston Chronicle -- SAN ANTONIO -- Lance Cpl. Rhonald Dain Rairdan was preparing for his last mission before his Marine Corps unit rotated out of Iraq when he called home on Monday.

"He told us that they were getting ready to get on a helicopter to go someplace for the (Iraq national) election," his father David said this afternoon. "Then they were going to go back to their ships."

David Rairdan said the 20-year-old Marine, called Dain by friends and family, was among the 31 service members killed when their helicopter crashed early Wednesday in a desert sandstorm in western Iraq.

He is the second San Antonio-area Marine known to have been on the Super Stallion transport helicopter.

Lance Cpl. Tony Hernandez, 22, of Canyon Lake, the helicopter's crew chief, was also killed in the crash, his family said Wednesday.

David Rairdan, who last summer retired from the Air Force after 24 years, said his son's unit deployed to the Middle East in October, about four months after he joined the Marines.

Dain, who grew up in Medina County just outside San Antonio, was a machine gunner stationed at Kaneohe Bay, Hawaii, as part of the 1st Marine Division.

"Most of the guys with him (in the helicopter) went through boot camp with him and they died with him," David Rairdan said. "We felt like we knew them through his cards and letters."

He described his son as very personable with lots of friends, and that he liked to be around people. As a Marine, his dad said, he was very good at his job.

Dain Rairdan's unit got to Iraq shortly before joining the Marine-led offensive to take control of Fallujah, an insurgent stronghold west of Baghdad, in November.

Afterward, his father said, his son's unit hunted for weapons caches in Fallujah and later was among those policing that combat-damaged city as its residents trickled back to their homes.

David Rairdan had also spent time in the Middle East as part of his Air Force duties, and he and Dain spoke several times about what was going on.

"I had been over there many times, and we understood what he was doing," the elder Rairdan said.

He said he and his family, which has a military tradition going back generations, aren't looking for someone to blame for Dain's death.

In his letters, David Rairdan said, Dain said he was doing what he wanted to do, and that he enjoyed what he was doing.

"We're looking at their positive things, that we had as much time with him as we did," the father said. "Of course it all hasn't sunk in. We haven't seen the coffin yet -- that's going to be a terrible thing. ... But sometimes bad things happen to good people."