D.C. police and D.C. Fire officials comb the scene at the 3200 block of Woodland Drive NW, where four people were found dead at a house fire. (Ricky Carioti/The Washington Post)

When Debra Masser spoke to her brother Savvas Savopoulos by phone Thursday morning, the chief executive and father of a prominent local family seemed to be untroubled and in good spirits.

But hours later, Savopoulos, his wife and two others authorities believe are the couple’s young son and their housekeeper were found dead by firefighters who battled a blaze at their Northwest Washington home.

Police on Friday continued to try to piece together what happened to the well-liked family, even as the mystery around the case deepened. D.C. Police Chief Cathy L. Lanier said that the fire at the stately home on Woodland Drive NW was intentionally set, that three of the victims inside had wounds, and that the family’s Porsche 911 was found torched in a church parking lot in Hyattsville, Md.

The deaths shocked family, friends and neighbors, who said they had seen nothing amiss with the five-member clan in the days and weeks before the fire. Some gathered to mourn at Washington National Cathedral, while investigators continued to pore over the charred red brick home.

“I can’t even express my sorrow,” Masser said. “I can’t even say anything.”

Savvas Savopoulos and Amy Savopoulos at the Starlight Children’s Foundation MidAtlantic’s Wine Dinner in 2008. (Tony Powell/Washington Life Magazine)

Lanier said police had positively identified two of the dead as Savvas Savopoulos, 46, and his wife, Amy, 47. They have tentatively identified the other victims as the couple’s 10-year-old son, Philip, and a 57-year-old housekeeper, Veralicia Figueroa, of Silver Spring, Md.

Lanier said that three victims suffered blunt-force or sharp-object wounds and that all four deaths in the upscale neighborhood near the vice president’s residence were being investigated as homicides.

“Evidence collection will go on for several days,” Lanier said. “There’s still a lot more we don’t know.”

Lanier renewed a call she originally made Thursday for information about the family’s blue 2008 Porsche 911, which disappeared from the home Thursday morning.

She asked the public to contact authorities if anyone had seen it between Wednesday and Thursday at 5 p.m. — a longer time frame than authorities had initially requested. Lanier declined to explain why investigators now wanted to know about the car’s whereabouts a day earlier.

The Porsche was found burning in Prince George’s County on Thursday evening, Lanier said. Prince George’s County Fire spokesman Mark Brady said firefighters extinguished the fire about 5:30 p.m. behind a church at 8201 Annapolis Rd. in Lanham, Md. Lanier said it was unclear who had been driving the vehicle.

Lanier said there was no evidence to suggest random or forced entry into the Savopouloses’ home but asked anyone who had seen anything suspicious in the area to call police. Asked whether the house had been ransacked, Lanier said it was “difficult to make that determination” because of the fire. Authorities have been going through the home to try to determine whether anything was stolen, according to two officials with knowledge of the case.

Police say three of the four victims found in a burning Northwest D.C. home on Thursday suffered blunt force or sharp object wounds. Their deaths are being investigated as homicides. (WUSA9)

The Savopouloses are survived by two teenage daughters, who friends said were at their boarding schools Thursday. Abigail Savopoulos is a senior at Mercersburg Academy, an elite private school in Pennsylvania, and is scheduled to graduate next week. Her younger sister, Katerina, is a junior at Peddie School near Princeton, N.J.

Philip was a student at St. Albans School in the District.

Neighbors said the family had lived on the block for more than a decade. They described the community as tightknit and said the Savopouloses were an integral part of it. They regularly held gatherings at their home for neighbors and friends. They attended church at the nearby St. Sophia Greek Orthodox Cathedral for about 10 years.

Coco Palomeque, a friend who lives in the neighborhood, said the Savopouloses were “a beautiful family.”

“The community where they lived really loved them,” she said.

Savvas Savopoulos was the president and chief executive of Hyattsville-based American Iron Works, which played a role in building Verizon Center and ­CityCenterDC. His Facebook page says he also worked for Sigma Investment Strategies in Puerto Rico. American Iron Works officials declined to comment.

Amy Savopoulos was widely known as a deeply involved mother who spent much of her time volunteering at her children’s schools or raising funds for them.

On her Facebook page, her daughter Abigail posted a tribute on Mother’s Day: “I am so grateful for everything you do. Thank you for always believing in me and supporting me. Thank you for the early morning crafts, upside down clowns on my birthday, gingerbread decorating parties, and for always showing up. . . . Thank you for the past 19 years and I look forward to the many more to come. I love you so much.”

About 180 people gathered to mourn the family Friday afternoon in a lower-level chapel at Washington National Cathedral. The 30-minute service included prayer, singing and periods of silence.

Many who had come were struggling not only with what happened, but also with how to discuss it with their children, said the Rev. Mariann Budde, bishop of the Episcopal Diocese of Washington, who helped lead the service.

“When people grieve, they want to be with other people,” Budde said. “Everyone is really sad, and really shocked.”

Rep. Chris Van Hollen (D-Md.), who has known the family for more than 20 years, said in a statement that he was saddened. Savvas Savopoulos raised money for Van Hollen’s campaigns.

“My heart goes out to the Savopoulos family at this time of unspeakable tragedy,” the statement read. “They were an important part of the community and will be deeply missed.”

As friends and relatives grieved, investigators wearing yellow hard hats walked in and out of the gutted Savopoulos home. Yellow police tape still blocked off sections of Woodland Drive and 32nd Street NW, and a large ATF explosives and fire investigation vehicle was parked out front.

Joe Carregal, a neighbor, said he saw the fire unfold Thursday. About 1:15 p.m., he said he saw smoke pouring from the upper-story windows of the home and a man knocking on the front door in an attempt to get the family out.

Soon after, fire trucks came roaring down the street. Firefighters broke windows on the house, deployed ladders and clambered onto the roof to extinguish flames. Carregal said he watched them pull three victims from the house.

Chris Vorobek, who lives in the neighborhood, said he would see Amy Savopoulos, walking her dog in the neighborhood, and her son racing around on his bicycle.

“He was a great kid,” Vorobek said.

Keith L. Alexander, Lynh Bui, Alice Crites, Abigail Hauslohner, Peter Hermann, Roxanne Roberts, Valerie Strauss, Julie Tate and Clarence Williams contributed to this report.