VERNON – Police said all seven of the people injured in Thursday’s house explosion in Vernon are lucky to be alive and they’re going to be okay. Vernon po...

VERNON – Police said all seven of the people injured in Thursday’s house explosion in Vernon are lucky to be alive and they're going to be okay.

Vernon police spokesperson Lieutenant William Meier called it a miracle that none of the people in the home were killed.

Investigators spent Friday trying to determine the cause of the explosion that destroyed the house at 4 East St. Thursday afternoon around 4:15 p.m. Here are the initial 911 calls made to alert police and firefighters about the explosion:

The Vernon fire marshal, Connecticut State Police and agents from the Bureau of Alcohol, Tobacco and Firearms are continuing to investigate. Police said they were working to eliminate causes, but that its not certain a cause will be determined any time soon, if at all.

Crews started early Friday morning, using an excavator in the rear of the house to sift through the debris. Investigators were also there taking photos and examining the wreckage. Lt. Meier said it's a delicate process to make the structure safe for investigators, as the rubble and debris are very unstable. He said they also have to be sure they preserve anything in the debris that may indicate how the explosion happened.

Police said there were propane tanks behind the home, but it's not clear if they were involved in the explosion.

Four of the people who in the home at the time of the explosion were trapped and had to be rescued, including a 7-year-old boy, 15-year-old girl, 23-year-old man and 35-year-old woman. Three others--two 12-year-olds and a 60-year-old man--got out on their own and were waiting for first responders outside the home.

All four children were taken to Connecticut Children's Medical Center. Of the adults injured, one man and woman were taken to Hartford Hospital while the 60-year-old man refused treatment.

At 3 p.m. Friday Lt. Meier provided an update on the condition of the victims: the 15-year-old girl and 7-year-old boy are now listed in good condition, a 12-year-old was released from the hospital and another 12-year-old is listed in fair condition.

The victims names were not released, but FOX 61 has confirmed with friends that the 35-year-old woman is Nicole Kerstetter. Most of the victims were related and were residents of the home, but police believe one person was just visiting at the time of the explosion. Lt. Meier also told FOX 61 at least two dogs were killed in the incident.

A source close to the family told FOX 61 that they are asking for privacy, but are in need of help; everything they owned was destroyed. Donations can be dropped off during business hours at the main office of the Vernon Public Schools, where several of the victims are students.

Vernon firefighters Assistant Chief Stan Landry, Lt. Dave Williams, firefighters Rich Harrison, Warren Boulette and Michael Levasseur were first on the scene and are being praised by their fellow first responders for rescuing the four people trapped in the house. Lt. Meier said their quick actions saved lives, but that it was a group effort from dozens of first responders.

Thursday, shortly after the explosion, Michael Hawley with the Connecticut Urban Search and Rescue Team described to FOX 61 how they were able to make sure everyone was out of the debris and accounted for. “Crews will go through in teams of four along with the state fire marshal and with their cameras. They can extend down into small areas and search around. They can move those cameras left and right up and down and they will look at every aspect,” Hawley said.

As for the kids, they are all expected to survive their injuries. Doctors at Connecticut Children's Medical Center couldn't speak to specifics, but did discuss the type of treatment the kids got.

“The thing that is extraordinary is that children tend to be very resilient and they really inspire us with how their able to tolerate these sorts of things and recovery much more quickly than we probably would as adults,” said Dr. Brendan Campbell, a pediatric surgeon for Connecticut Children's Medical Center.

Dr. Campbell couldn't speak to the specific injuries the children sustained, but said did speak about the types of injuries that patients in explosions, such as those in Iraq or Afghanistan, typically sustain.

Campbell explained that significance of these types of injuries depend on how close the victim is to the blast, varying from ruptured eardrums, to internal injuries, broken bones, burns and other more minor injuries. He couldn't say if any of them required surgery, but said that these types of injuries can be significant and often times do require surgical intervention, as well as ICU care.