ACCIDENTAL OVERDOSE SUSPECTED

Police Say Couple Had 'Laughing Gas'

The man and woman found dead in their Mechanicsville bedroom Wednesday were
wearing clear respiratory masks over their noses and mouths that led to
large canisters of nitrous oxide, the St. Mary's County sheriff's office
said yesterday.

Police said the bodies of Carol J. Smith, 29, and Mark A. Trowbridge, 40, a
paramedic for the D.C. fire department, were found lying lifeless in bed
Wednesday afternoon when Trowbridge's 14-year-old son arrived home from school.

Although the cause of death had not been confirmed, police said the pair may
have overdosed accidentally while using the gas to produce a euphoric high.
One drug expert suggested they may have passed out with the masks on and
continued to inhale the nitrous oxide until they suffocated.

Nitrous oxide is the "laughing gas" anesthetic used by many dentists. It is
commonly abused by teenagers, who buy small pressurized containers of the
gas, known as "whippets" because they are used to power whipped cream
containers sold by restaurant supply companies and gourmet food stores.

Trowbridge and Smith apparently had been dead for several hours before
Trowbridge's son discovered the bodies at the home in the 27300 block of
Bosse Drive. The 14-year-old had not spent the night in the home and
returned that afternoon and found his younger sister and Smith's two
children -- all younger than 11 -- playing in the mall split-level house in
the Country Lakes subdivision in St. Mary's County. The children told police
that neither Smith nor Trowbridge had awakened them for school, so they had
remained home all day.

Sheriff's Lt. John Horne said investigators were uncertain where the couple
obtained the gas but believe that one of them may have illegally obtained
the medical-grade nitrous oxide.

D.C. fire officials said that their paramedics do not use nitrous oxide and
that Trowbridge would not have had access to it while performing his
day-to-day duties, although he frequently was in hospitals where the gas was
used. They said Trowbridge had not been suspected of having a drug problem,
nor had he ever been sent for drug
testing or substance abuse counseling.

He was "one of the most educated and highly trained people we had," said
battalion Chief William Mould, the D.C. fire department public information
officer.

Trowbridge had been a paramedic with the fire department for 10 years,
stationed at the fire house at Fourth Street and Rhode Island Avenue NE,
fire officials said yesterday. He worked in the special operations section,
which includes specialized units that deal with hazardous materials and
confined-space rescues. He also was a specialist in "high-angle" rescues in
which emergency personnel rappel off the sides of buildings.

Yesterday, friends of the pair struggled to understand how two such people
- -- one a veteran medical professional, the other an aspiring paramedic --
could have died experimenting with a controlled substance.

"It's a terrible, private tragedy," said John W. Roache, the president of
the Mechanicsville Volunteer Rescue Squad Inc. "What people do in the
privacy of their homes, we don't know. It's a tragedy for their families,
for this squad and for the community."

Roache said that Trowbridge spent much of his off-duty time responding to
car accidents and fires in St. Mary's County. Smith was in training to be an
emergency medical technician with the Mechanicsville rescue squad.

Friends said that Trowbridge had been under stress in recent months caused
by a separation from his wife and the illness of two family members.

"He had a lot of trauma going on in his life," Mould said. "It's just very sad."

Trowbridge and his wife of 20 years, Mary, an employee of the St. Mary's
County Board of Education, separated last year and filed for Chapter 7
bankruptcy in October, court records show. Their case was discharged in
February.

Mary Trowbridge, who also was a volunteer emergency medical technician for
the Mechanicsville rescue squad, moved out of the couple's home. Smith and
her two children had moved in only recently, neighbors said.

Staff writer Maria Elana Fernandez contributed to this report.