MANILA, Philippines?(UPDATE 5) Four people aboard a private plane were killed when the aircraft crashed into a warehouse and burst into flames in Las Piñas City past noon Saturday.

Witnesses said they saw smoke coming from the DC-3 aircraft owned by Victoria Air minutes before it hurtled down onto the former bus terminal at Villa Fidela Subdivision in the village of E. Aldana around 12:30 p.m.

The vintage cargo plane left the old domestic terminal in Parañaque at 11:56 a.m. and was on its way to Palawan when it crashed into the residential area, said Roberto Uy, chief operating officer of the Manila International Airport Authority.

"Nakita ng tanod ko na umuusok na yung eroplano at mababa na, halos dumidikit na sa poste. Tumama yung left wing sa poste tapos bumagsak, tapos maya-maya sumabog na," said Rudy Garcia, barangay captain of E. Aldana.

Firetrucks and rescue teams from all over Metro Manila rushed to the site to put out the fire that lasted until 2:15 p.m. Six drums of aircraft fuel carried by the plane may have contributed to the blaze.

Alhough 15 houses on San Francisco Street behind the warehouse were damaged due to the blast, no other casualties were reported aside from the four male victims.

"As per the flight manifest, seven people were listed but we confirmed that only four boarded the plane. These were the pilot, co-pilot, a mechanic and a passenger," said Jose Sablan of the Civil Aviation Authority of the Philippines.

Sablan, who chairs the CAAP's Aircraft Accident Investigation and Inquiry Board, said they withheld the victims' identities from the media pending notification of the victims? next of kin.

Burnt debris of the two-propeller plane scattered all over the warehouse and the grassy lot. A large part of the empty warehouse's roof was burnt.

"Based on our impression of the scene, the pilot led the aircraft to a clear area to land. But it's still aligned to the runway," Sablan said.

He said the plane, often used to transport fish, was on a regular flight?not a test as broadcast media had reported?but did not have any cargo.

"They may have intended to pick it up from Palawan," he added.

Warehouse caretaker Glenda Gallano said she was sweeping dirt on a nearby concrete pavement when the plane suddenly crashed.

"Pagbagsak, umusok ng makapal tapos sumunod na yung apoy. Hinabol ako ng apoy kaya nagtatatakbo na ako. Inisip ko yung mga anak ko kasi naglalaro sila kanina dun; buti na lang wala na sila dun," she said, still shaking.

Gallano said she was thankful for escaping unscathed since her family lived in the warehouse, which was formerly a bus terminal until it was foreclosed by Security Bank years ago.

Sablan said it was difficult to speculate on what caused the crash.

"Since the weather was okay, it's possible that it could be engine trouble or pilot error. But we don't want to speculate," he stressed.

The MIAA?s Uy said initial information showed that the plane radioed the tower shortly after takeoff and asked for "priority to land."

"It's already a distress call. Kasi pag takeoff mo at may napansin kang hindi maganda, you take Plan B. That was the last they (tower) heard about the plane," he said.

The CAAP, however, may have difficulty probing the incident as the old-model plane did not have a black box or a voice recorder.

But questions about the airplane's airworthiness arose as the same aircraft reportedly experienced trouble three weeks ago.

"It lost hydraulics. Landing from Bacolod, nawalan ng preno so it had to be towed from the runway. We're actually not yet finished investigating that incident," said Amado Soliman, a member of the CAAP accident investigation board.

All planes are certified "airworthy" before they are allowed to fly, he added.

"The DC-3s came up since the early 1940s so it's old," said Soliman. Uy, however, clarified that a plane's airworthiness should not be measured by its age.

The Las Piñas police said they will only support the investigation of the CAAP, which claimed authority to probe airplane-related incidents within an eight-kilometer radius of the airport.

The charred bodies of the victims were taken to the Filipinas Funeral Homes in Pamplona 3 for proper identification.