SIOUX FALLS, S.D. (AP) — The National Park Service is finally beginning to excavate the opening of an unexplored cave in the Black Hills of South Dakota that researchers believe could help broaden our understanding of how the region’s climate has changed over thousands of years.

Employees at Wind Cave National Park discovered Persistence Cave in 2004. The federal agency kept it secret, partly to prevent amateur spelunkers from exploring on their own until they could get inside.

A team of scientists, led by East Tennessee State University professor Jim Mead begin excavating the cave Monday.

Mead says preliminary samples from the cave shows bones as old as 11,000 years, or around the latest Ice Age. He says looking at which animals lived in the region then will help understand how it’s changed.

MCCOOL JUNCTION, Neb. (AP) — Flood concerns are easing along the Big Blue River in southeast Nebraska.

Residents in part of McCool Junction had been urged to evacuate Saturday as the Big Blue River threatened. But conditions improved Sunday because no additional rain fell overnight.

McCool Junction village chairman Steve Green says the community plans to spend Sunday cleaning up the sand bags it set out a day earlier.

Water damage was reported in two homes on the south side of McCool Junction, including one with five feet of water inside. At least four homes in another neighborhood also had damage.

Several county roads remain closed with water over them and roads crossing the river in York County were closed Sunday.

In Beatrice, officials reopened U.S. 136 Sunday morning.

OMAHA, Neb. (AP) — Omaha police are investigating a crash that killed a 6-year-old boy and a motorcyclist late Saturday.

Police say the motorcycle was speeding when it crashed into the passenger side of a Ford Escape in northeast Omaha.

The 6-year-old Chance Delaney was riding in the back seat of the SUV, and he died from his injuries.

The 20-year-old motorcyclist, Gage Adam Tyler Dawes, also died.

The Ford’s front-seat passenger, 29-year-old Ejay Edmond White Jr., was taken to a hospital with head injuries but he is expected to survive. The SUV’s driver, 20-year-old Brooke Bodnar, suffered only minor injuries.

LINCOLN, Neb. (AP) — Authorities have identified the elderly man and woman who died in a weekend house fire.

Lincoln Police said 74-year-old Ervin Martin and 69-year-old Janice Ortiz died Saturday night in the fire.

Initially, firefighters thought they were responding to a medical problem, but they encountered smoke and flames when they opened the door of the home near where Interstates 80 and 180 meet.

Fire investigators determined that a lit cigarette started the fire.

Autopsies will be performed to confirm they died from fire-related injuries. Authorities believe Martin and Ortiz died from smoke inhalation and burns.

LINCOLN, Neb. (AP) — Authorities say a Nebraska woman followed her ex-boyfriend onto Interstate 80 and rammed his car several times.

The Lancaster County Sheriff’s office says the incident happened near Lincoln around 4:30 a.m. Saturday.

The sheriff’s office says the 40-year-old woman followed her ex-boyfriend onto I-80 and rammed his car repeatedly.

The ex-boyfriend told authorities that the woman is upset about a recent breakup.

A passenger in the ex-boyfriend’s car sustained minor injuries.