Two siblings aged just nine and 11 are being hailed heroes after helping their mother deliver their baby brother.
Faith and Jabari Sanders, from Fremont, California, called their father and 911 and got advice from an emergency dispatcher.
They fetched towels for their mother and even tied the snapped umbilical cord.
Faith, aged 11, told the San Francisco Chronicle: "I never thought that something like this could happen.
"Usually, nothing happens every day. It's the same-old, same-old. But this time something new and exciting happened."
Jabari, 9, added: "I thought it was kind of cool and weird because he was born in a bathroom."
Their mother, Alana Sanders, 36, had always had quick labours but this one took even her by surprise.
Her husband Geoffrey had gone to work when she started having pains, and soon the baby was on its way.
Mrs Sanders told Jabari to call 911 and told Faith to call her father to tell him to come home, but things moved too quickly for any help to arrive.
After just one push, baby Joseph, weighing 9 pounds and 4 ounces, came out and fell onto the bathroom floor.
A 911 recording shows that both children stayed calm and talked to the emergency dispatcher and their mother.
The dispatcher checked the condition of the baby and mother. She gave the children directions on how to clean the baby and told the mother to lie down.
Faith was then given directions to carefully tie off the cord, which she did with knitting yarn.
The dispatcher told her: "You did a great job."
Mr Sanders said he was very proud of his children. "As a husband, you always want to be superman in your family," he told the Chronicle. "I wasn't able to do that. But my kids were the superheroes this time around, and that's fine with me."
Source: San Francisco Chronicle