Alvarez gave the seven-member board 30 days to complete its inquiry and submit a report.
A team of investigators has been dispatched to Lucena City to determine what caused the fire that swept across the MV Maria Carmela, a 680-ton vessel with at least 290 people and several vehicles on board.
Government regulators have grounded the rest of the fleet of Montenegro Shipping Lines, which owned the Carmela, pending an inquiry into the seaworthiness of its vessels, said Oscar Sevilla, an official of the Maritime Industry Authority (Marina).
The investigators were not immediately able to board the vessel, which is still on fire off Lucena, said Lt. Cmdr. Elpidio Gunio, the district Coast Guard chief.
"No one has been able to board the ship because of the heat," Lucena Mayor Ramon Talaga said. Investigators expect to find more bodies aboard the floating wreck.
"Our latest report is that 28 people perished," Coast Guard chief Vice Adm. Reu-ben Lista said. Nearly half the dead were children.
Lista said some of the 70 people hospitalized because of first- and second-degree burns were in critical condition.
A Montenegro company official said the firm will shoulder the victims medical expenses, while relatives of the fatalities will each receive a P100,000 indemnity.
More than 200 people were rescued, including the ferry captain. The Office of Civil Defense (OCD) said around two dozen people remained missing.
Workers from the Department of Social Welfare and Development were sent to Lucena to help survivors and relatives of the dead cope with the emotional trauma.
Coast Guard district official Lt. Cmdr. Lorenzo Princesa said an initial investigation indicated that more than 290 people were aboard the vessel, which was authorized to carry 334.
He said the ferry, which set sail from Masbate late Wednesday, carried a number of trucks packed with dried coconut meat and live cattle. The trucks "have drivers and escorts, and they were not listed in the manifest," Princesa said. They were not listed because, unlike the trucks, the drivers are not paying passengers.
A report from Ricardo Nicolas, officer-in-charge of Montenegro Shipping Lines, to the Coast Guard showed that the Carmela was overloaded.
Aside from 243 passengers listed in the manifest and 28 crewmen, the Carmela was carrying 81 non-paying passengers who included 24 truck drivers, eight car drivers and escorts, and 21 pass-holding passengers.
Among those missing is the wife and three children of one Salvador Alvarante, who were reportedly not listed in the manifest. Montenegro gave them free passage because the family owned a trucking firm, one of the companys regular clients.
The wife reportedly helped distribute life jackets to fellow passengers until the fire trapped her on one of the decks.
The OCD said survivors told how the fire broke out in the ships hold. The coconut meat raw material for vegetable oil served as fuel to the fire, it said.
Aside from that angle, investigators also suspect that the fire was started by a discarded cigarette butt, or by a cooking fire, or a spark triggered by a vehicle whose engine was running.
Survivors said panicking passengers on the ferrys upper deck hurled themselves into the sea, many without putting on life jackets. Lista said it appeared that there were not enough vests because the ship was overloaded.
The Carmela caught fire around 7:30 a..m. last Thursday near Pagbilao Chica island, about an hour away from Lucena, its destination.
Princesa said the Carmela passed a Coast Guard seaworthiness inspection last month, but De Villa said the government has "issued an order to ground all their vessels" pending a new inspection.
The Coast Guard inquiry board would subpoena crew members and other witnesses, Lista said.
Marina said it would revoke Montenegros license to operate if found guilty of violating maritime regulations. Lista said criminal and administrative charges would also be filed against Coast Guard inspectors would have been remiss in the inspection.
The tragedy is the latest in a long line of shipping disasters that have claimed thousands of lives in the country over the past 15 years. With reports from Sheila Crisostomo, Perseus Echeminada, Rainer Allan Ronda, Celso Amo, Arnell Ozaeta