(CNN) The Pennsylvania home day care where five children died in a fire early Sunday wasn't inspected by state or local authorities for smoke detectors because of loopholes in regulations, officials said Tuesday.

The Harris Family Daycare in Erie, where a blaze killed four siblings and a child of the owner, apparently didn't have enough smoke detectors , Erie Fire Chief Guy Santone said. Investigators located only one in the house, he said; it was in the attic. State regulations indicate there should have been one on each floor of the two-story home.

Pennsylvania's Department of Human Services carried out the yearly safety inspections at the facility. DHS' fire-safety checks include exits, space heaters, fire places, wood and coal stoves and fire drills, DHS Press Secretary Erin James said in an email to CNN, but "the current regulations do not allow for citing a child care facility for compliance with fire safety codes including the presence and functionality of smoke detectors."

"This is an unthinkable tragedy, and we are committed to working with other state agencies and local partners to ensure that child care facilities are properly monitored for smoke detectors in the future," James said. "We are committed to closing this gap and all options, including amending DHS' existing regulations, will be considered in the immediate future."

"If the Department of Human Services observes a possible fire safety violation, it will request additional fire safety inspections by the appropriate agency," in line with state codes, James said of the current process.

Santone said the city inspects for smoke detectors and fire extinguishers. However, Harris Family Daycare was not registered with the city government because a "loophole" in regulations meant that any child care facility founded before 2004 only had to register with the state, he said.

"When they (state officials) do their inspections, they don't inspect for smoke detectors. They don't inspect for fire extinguishers. They inspect for things like cleanliness, make sure that there's nothing laying around that a child can choke on, things of that nature," Santone said of the DHS, speaking at a press conference Tuesday. "That has to stop."

Eight people were on the second floor of the house when the fire broke out around 1:15 a.m. in the first floor living room, Santone said.

The fire chief indicated that inspectors are focusing on an extension cord as the cause of the blaze.

Two teenagers who escaped the fire were alerted by the house's one smoke detector, which was in the attic, Santone said. They got out by jumping from a second-floor window onto a porch of the home. By the time the detector went off, the house was already filled with smoke, Santone said.

State Sen. Dan Laughlin said he has drawn up legislation to have smoke detector checks added to DHS inspections of day care facilities.

"Unfortunately, it can happen again, because there's thousands of these day cares across the state of Pennsylvania that are unprotected right now, at least as far as we know," Laughlin said at the news conference.

The day care had an active "certificate of compliance," state records show. The latest inspection of the home, in December, cited several things that needed correcting, including protective covers on electrical outlets and the removal of ashes and cigarette butts. The inspection did not mention any concerns with fire safety.

The victims were between the ages of 9 months and 8 years. Three of the four siblings were children of a firefighter from nearby Lawrence Park Volunteer Fire Department.