Delray Beach, FL – Her voice tired, her body drained, Susan Sprague wondered out loud what led to her parents’ death.

Murray Zadan, 83, and his wife, Naomi, 78, were one of two couples who died of carbon monoxide poisoning Wednesday in the Lexington Club community in suburban Delray Beach. Authorities said a red Dodge Caravan was left running in a garage for most of the day. The van belonged to Murray Zadan, Sprague’s father. “He’s not likely to do something like that,” Sprague said of her father’s leaving the keys in the van’s ignition.

“There had to be something. … My mother called him quickly?” she asked. “Something like that?”

Between taking phone calls from shocked loved ones and planning for two funerals, Sprague has had little time to grieve. As she stood in her parents’ quiet house Thursday, none of it seemed real.

“I’m expecting them to come out and say hi,” she said.

The community where the two couples lived is in a “state of suspension” after the deaths, friend and neighbor Ronald Jacobson said.

“They loved everyone, and everyone loved them,” Jacobson said of the second couple, Eliot “Pepe” Levine, 78, and his wife, Mildred “Molly” Levine, 76. “They were truly special people.”

The deaths prompted nearby residents to buy carbon monoxide detectors first thing Thursday morning. Some bought several and handed them to neighbors, and many said they want the association to require all residents to install them.

Palm Beach County fire rescue workers found Murray Zadan in the bedroom and his wife in the bathroom of their second-floor condominium at 7840 Lexington Club Blvd., where tests showed an extremely high reading of carbon monoxide.

Before the Zadans were found shortly after 10 p.m., their downstairs neighbors, the Levines, were found dead. Investigators believe the poisoning was accidental.

Since Wednesday, many have asked Capt. Don DeLucia, spokesman for county fire rescue, how someone could leave a vehicle running for so long and just not know.

DeLucia struggles to come up with answers. Someone could be in a hurry or just forget. Maybe the driver did not hear the motor.

He said carbon monoxide deaths can occur within two to three hours of exposure.

Both couples, originally from New York, had lived in the Lexington Club community for 18 years.

The Zadans celebrated their 59th wedding anniversary April 10, and Murray Zadan celebrated his 83rd birthday Saturday. His wife, Naomi, had a stroke several years ago and moved around with the aid of a walker and a wheelchair.

The van had a hydraulic lift so Murray Zadan still could treat his wife to nice dinners and peaceful drives.

Neighbors say that after his wife fell ill, Zadan became her nurse. He cleaned, shopped and cooked, with soups being his specialty.

The couple owned a candy store in New York and then a shade installation business in Sunrise before moving to Palm Beach County. Zadan was president of the condominium association and was supposed to bring doughnuts to Wednesday night’s board meeting. When he did not show, worried residents called the sheriff’s office.

The couple had two children, Sprague and Craig Zadan, a producer in Los Angeles linked to award-winning movies, including Chicago and the upcoming remake of Hairspray.

Charlotte and Walter Lechten live in the same building in a second-floor apartment. Authorities found a small amount of carbon monoxide in their apartment and in the unit below theirs.

“We would have been next,” Charlotte Lechten said. “I’m frightened right now. I’m shaking.”

Pepe Levine was an avid bowler, and though he had multiple sclerosis and walked with a cane, he was dedicated to the Lexington Club bowling league. His wife, Molly, was the league secretary and had planned a bowling banquet for next week.

“Molly I adored,” said neighbor Gloria Milmar. “It was always a hug and a kiss.”

Pepe Levine was a member of the men’s club, and his wife was head of the social committee. While in New York, they owned various meat markets. He was a butcher, and she helped with the business.

They had two children and were married 55 years.

“We couldn’t understand it,” neighbor Sandy Diamond said of the deaths. “They just went to sleep. It’s very sad.”

DeLucia plans to see whether local hardware stores will partner with fire departments to promote carbon monoxide detectors in the coming weeks.

“We probably get a dozen a year easily of carbon monoxide issues,” he said. “They don’t all die, but they’re more common than people think.”

Zadan’s daughter does not have a carbon monoxide detector in her home but plans to buy one soon. And DeLucia hopes many others follow suit.

“All you can do is try to educate,” DeLucia said. “If they had a carbon monoxide detector, they’d be alive.”