A technology executive, his wife and four grandchildren were feared dead in a suspicious fire that destroyed their home in Annapolis, Maryland, Monday. The mansion was owned by ScienceLogic Chief Operating Officer Donald Pyle, a company spokesperson said.

The fire started on the second floor of the seven-bedroom home before 3:30 a.m. WJLA, Washington, reported it took 85 firefighters until 7 a.m. to stop the blaze, which reduced the 16,000-square-foot house to ashes.

Pyle is believed to have been asleep in the waterfront home along with his wife, Sandra, and four grandchildren. The Anne Arundal County Fire Department is investigating the fire as “suspicious,” along with a response team from the Bureau of Alcohol, Tobacco, Firearms and Explosives, CNN reported.

Until a cause is determined, investigators are treating the home as a crime scene. Anne Arundel County Fire Capt. Russ Davies tweeted news about the fire, detailing fire crew's difficulty putting out the fire due to the secluded location of the mansion. Teams had to transport water hundreds of feet from a fire boat on a nearby creek to the home in fire hoses to fight the blaze.

Pyle was hired by ScienceLogic in October of last year, a statement said. Previously he had acted as executive vice president at Infoblox and CEO of Netcordia as well as Laurel Networks.