Bad weather had made it impossible to proceed with a planned taping for the Animal Planet channel, so Irwin chose Monday to shoot "a couple of soft stories for a new TV show we're doing," Stainton told CNN when the news broke.
"He and the underwater cameraman went out to do some pieces on the reef and coral and stuff good for the kids' show and, unfortunately, he came out over the top of a stingray that was buried in the sand and the barb went up and hit him in the chest," Stainton said Monday.
"He was as good on the water as he was on land," Stainton recalled Tuesday. "He was comfortable anywhere there was wildlife. He'd been diving 10, 15 years ... I never thought he'd take a hit from a stingray. He was very used to them."
Only the day before, he, Irwin and a doctor on board had discussed stingrays and the effects of their barbs, Stainton said. Stingrays, however, were not to be included in the "dangerous animals" documentary. (
Watch how a stingray strikes -- 2:35 )
Stainton said he had to watch the tape in order to verify what was on it. "It was a hard experience," he said.