BAGUIO CITY, Philippines -- American experts have also concluded that the explosion at the Glorietta shopping mall in Makati City on October 19 was "a tragic accident" that cost the lives of 11 people, US Ambassador to the Philippines Kristie Kenney said here on Tuesday.

Earlier, a team of investigators from the Australian Federal Police submitted a report to the Philippine National Police that it found no evidence of an explosive device from the debris. The PNP said the explosion was likely caused by accumulated gas in the mall's basement.

Kenney said those who say otherwise should realize what a terror attack in Metro Manila would mean to the country.

The ambassador, who was in Baguio City for several engagements, kept correcting reporters who referred to the blast as a "bomb attack," repeating to them that it was "an explosion."

An accident in the heart of a city "is never a good thing," she said. "But it is much better than having it to be a bomb. If there was a bombing at a shopping mall in the middle of Metro Manila, I want you to think about the kind of travel advisory America would have to put out and the devastating impact that would have on business."

"I don't think investors worry about an accident," she added, although the business community "would obviously want to know why it happened."

The only US Embassy advisory still in place warns American citizens to be cautious when they travel to some areas in the southern Philippines, she said.

"A tragic accident is exactly that… a tragic accident," Kenney said.

"We were horrified [when we heard about the explosion]. That is the place where we shop. I shop there often. That is where the people go often. And in fact we lost good friends of the embassy -- a couple of family members of Filipino employees of the embassy," she told the Philippine Daily Inquirer at a Monday dinner she hosted for local reporters.

On Tuesday, when she hosted the Veteran's Day celebrations at the Ambassador's Residence inside Camp John Hay, Kenney again told reporters that the US was satisfied with the findings that the blast was an accident.

"Our experts have communicated this to the [PNP]…. Maybe the police could conclude their investigation and take all of the evidence into account. That's their job. We're merely here supporting them," she said.

Kenney made no references to terrorism, except to reiterate the Philippines' alliance with the US-led war on terrorism.

"The forces of the Philippines and the United States defend our peace from those terrorists who would deprive us of the opportunity to live in freedom and [to] enjoy our prosperity," Kenney said in her speech during the Veteran's Day ceremony.