Flavia Lombardi Giampietro, 80, was about to be flown to the Maryland Shock Trauma Center in Baltimore after being freed from her wrecked vehicle, but her condition quickly deteriorated, making such a flight risky, said Battalion Chief Matthew Tobia, a county Fire Department spokesman.

He said the woman went into cardiac arrest and stopped breathing.

As protocol, paramedics canceled the helicopter and drove Mrs. Giampietro to Anne Arundel Medical Center in Parole - the closest hospital. Her injuries were grim.

"When we get into a situation where we have an elderly female with critical injuries and she loses a pulse and is not breathing, it's almost always not survivable," Chief Tobia said.

At the hospital, doctors and nurses fought to keep Mrs. Giampietro alive and eventually were able to re-establish a pulse.

She was taken to the shock trauma center, where she remained in critical condition this morning, police said.

Her husband, Dominick Michael Giampietro, 83, of Rockville was driving a 1997 Chrysler LHS east on Mayo Road at 1:30 p.m. when he sloweddown and turned left to go to the Peninsula Farms & Bait stand, county police said. The Chrysler pulled directly into the path of a 2003 Ford van that was traveling west, and was struck on the passenger side.

Mrs. Giampietro, was in the front passenger seat during the crash.

Mr. Giampietro was taken by ambulance with serious injuries to Anne Arundel Medical Center, where he was treated and released to be by his wife's side at the shock trauma center, officials said.

The driver of the van, Felipe J. Guerrero Castellanos, 23, of Gaithersburg and his six passengers were not injured, police said.

Police shut down one lane of Mayo Road near Selby Heights Road for more than an hour while they reconstructed the accident scene. Traffic backed up more than 2 miles in both directions, causing many drivers to turn off their vehicles and chat on the roadside.

Mr. Guerrero and the van's six passengers sat in a grassy lot next to the bait stand. An investigator jotted in a notebook as the men told him what happened.

Teirra Harris, 25, of Mayo was folding laundry at the Mayo Cleaner when she said she "heard a big bang" and the sound of brakes slamming. She said paramedics pulled Mrs. Giampietro from the crushed green Chrysler and began cardiopulmonary resuscitation.

"They took her behind the legion, but then it didn't (look like) she was going to make it," Ms. Harris said. "The man, he was in a state of shock. He looked like he was in a daze.

"He walked up to an ambulance and they took him to Anne Arundel (Medical Center)."