By Anne McNamara

(WAVY/CNN) - A pregnant woman described as a good swimmer by her family, drowned off North Carolina's Outer Banks on Wednesday.

Authorities say the 31-year-old mother-to-be slipped off a sandbar while she was with her husband.

Jill Bailey Chenet and her husband, Matthew, were enjoying their vacation on the Outer Banks when it abruptly ended Wednesday night while the two were swimming in Buxton.

Pastor Jim Parke said the couple lost their footing on the edge of a sandbar.

"And then all of the sudden, it dropped," said Parke.

Parke says Matthew tried to save Jill. He struggled to keep her afloat for 20 minutes before help arrived.

"He just kept holding on to her but he realized at one point he realized she had turned blue, that kind of thing," he said.

Park rangers found the couple 20 yards from the shore. Jill wasn't breathing when they got there, she had no pulse, but they flew her to the hospital where Matthew had the chance to say goodbye and ask Parke for a favor.

"He insisted that I bless, at this point, the deceased infant. 'I want you to bless Olive,'" said Parke.

The couple had already chosen a name for their little girl. Baby Olive was their first child. She was due in November.

For Matthew, the loss is twofold. The pain unimaginable.

"It's gonna be a big adjustment for Matt. Because he's losing two," said Parke.

Chenet grew up in Salem, Virginia and was living in Washington D.C.