Transcript for Stories of survival emerge after London high-rise fire

Back now with new details about that tragic fire in London. Stories of survival emerging as authorities investigate what sparked the blaze and ABC's James Longman is on the scene in London with more. Good morning, James. Reporter: Good morning, Michael. Yes, the queen has offered her condolences this morning and the prime minister Theresa may has been to visit the site. The death toll currently stands at 17 but we're told that is likely to rise significantly. Let me out! Reporter: This morning new video from inside that massive inferno in the heart of London. We're stuck on the 25th floor. Hello. There's too many people stuck upstairs. Reporter: This as we're learning more tales of desperate attempts for survival. Witnesses saying a baby fell nearly ten stories to safety. Miraculously caught by a bystander nearby. A lady appeared at the window. From what she was saying I'm about to throw my baby, please catch the baby. This was an unprecedented fire in terms of scale, speed and spread. Reporter: This morning, firefighters are still battling hot spots of the fire using drones to see inside parts of the building they can't gain access to. We're using drones to be able to create access and visibility to certain parts of the building to be able to assess the integrity of the building. Reporter: Adele, one of the celebrities who came to lend support to the victims. Twitter users sharing pictures of the star who appears to be wiping her eye. The cause of the fire killing at least 12 and injured at least 74 still unknown. Some residents say they complained about the building's safety for years. The Grenfell tower underwent a major refurbishment program about 2 1/2 years ago and we will need to look much more closely at how much of that corresponds to the cause of today's fire. Reporter: The management company saying we will cooperate fully with all the relevant authorities in order to ascertain the cause of this tragedy. Firefighters have been inside the building but he can't do a comprehensive search until its integrity has been assured. There is a lot of anger here. Residents asking how something like this could have happened. Michael. All right, thank you, James. A lot of questions to be answered and we're joined now by Cal fire battalion chief Mike Mohler in Riverside California. Chief moellhlermoehler, thanks for joining us. If you live in a high-rise or apartment and the fire alarm goes off, what should you do? Well, good morning, Michael. Thank you for having us. First I want to say our hearts and our prayers are with the family and loved ones affected about that tragedy. If you are hear a alarm regardless of whether you see smoke, fire, you need to evacuate that building and do it every time that alarm should sound. What if you're trying to leave your apartment, the door is warm and smoke coming in under the door what is your next step then? Next step is if you have smoke coming under your door, if you have heat is to put a towel at the base of that door to call 911 and let them know exactly where you are, your apartment number, how many people are with you so emergency officials know exactly where you are in that structure. And chief mohlor, you say the number one mistake they make is they're unprepared to are a fire so how do you make an evacuation plan. What is the best way to do that? That's correct, preparation is what we call our prevention for citizens when they live in a high-rise so what you need to do is, one, know your exit routes throughout the building. Know where your stairwells are, the quickest way out but also exercise that with your family and literally walk through that evacuation plan with your family as a group and form up outside of the building itself so everybody knows where to come together if there is an emergency. Well, chief Mohler, thank you so much and advice all of us need to heed. Thank you very much.

This transcript has been automatically generated and may not be 100% accurate.