The tense minutes ticked past, but the distinct wail of an ambulance was not among the noises at the Fairfax County industrial park early Monday.

The 50-year-old employee of Waldron Inc., an air-conditioning and heating company, was having a heart attack, and all his colleagues could do was watch and wait, the business's owner said yesterday.

Medics arrived 14 minutes after Waldron workers first called 911. The man, whose name was not released by the company or by authorities, later died at Inova Alexandria Hospital.

Authorities blamed the wait on a misrouted 911 call. Waldron, where the man worked for 24 years, is at 5910 Farrington Ave. in Fairfax County, but the road crosses the Alexandria-Fairfax border.

At the company's office yesterday, owner Floyd Smith added details to the story released Tuesday by Alexandria and Fairfax authorities. Smith said an employee called 911 shortly after 8 a.m. to request an ambulance.

The employee was told that he had reached the wrong call center but that the information would be transferred to the appropriate jurisdiction, Smith said.

"He was told that Fairfax County would call back for the information, but Fairfax County did not call back," Smith said.

Minutes passed. The employee phoned 911 a second time, Smith said, and again the call was answered by an Alexandria call-taker.

"This time the transfer to Fairfax was made with [him] on the phone," Smith said. "The two dispatchers were going back and forth as to which had responsibility for the call. The Waldron co-worker told them he didn't care who came, but to send them right now."

Alexandria sent one ambulance and one fire engine, said Jane Malik, a spokeswoman for the department. The units arrived at 8:17 a.m. People there already were administering CPR.

"No one can change what has happened, but I hope that changes are made quickly to prevent this kind of confusion in the future," Smith said.

Fairfax authorities acknowledged Tuesday that the address was in their county, and they said they are investigating the incident. County police command the dispatch center for police and firefighters. Fairfax responds to about 75 percent of medical emergency calls in six minutes or less, its most recent statistics show.

Fairfax and Alexandria operate under an agreement that allows them to share responsibility for emergency calls. Medical and firefighting units that are closest to an emergency will respond, said Dan Schmidt, a spokesman for the county's fire department.

"The boundaries we have are geographical and political, but in the public safety arena, we don't have boundaries," he said yesterday. "If someone needs help and it's only two streets away but it's outside our jurisdiction, the closest unit will respond. That is our policy. It's how we operate."

Still, there was a breakdown Monday, he said, and officials are reviewing the dispatch system and other recent calls along the border, he said.

"Sometimes systems don't always go according to plan," he said. "There are technical challenges, human error challenges and other things that can get in the way. In this particular case, we just don't know what happened."

Officials in both jurisdictions also faulted Verizon Communications for not correctly routing the initial 911 call.

Harry Mitchell, a spokesman for Verizon, said the company is "fully investigating the whole issue and working with both jurisdictions."

"We recognize that jurisdictional lines are pretty challenging," he said.

No cause of death was available yesterday, and officials said it was not clear whether a rapid response would have saved the man. Smith said the man's family was aware of the circumstances of his death but did not want to comment immediately.