SAN FRANCISCO -- It was just after 3 p.m. when Linda Schoenfeld and her husband, who were visiting San Francisco on vacation, found themselves walking in Washington Square park.
"We heard this 'crack,' we looked up and all of a sudden this big branch comes down," Linda Schoenfeld said.
The Seattle couple saw a little girl standing near a woman lying on the ground under a large pine branch that had fallen from about 50 feet above the park bench where the woman had been seated, reports CBS station KPIX.
"She had a pool of blood under her head and she wasn't moving," Mitchell Schoenfeld remembers.
Linda Schoenfeld jumped into action, keeping the 37-year-old mother of two from moving until paramedics arrived.
"She was unconscious when we got there and, while I was taking her pulse, she took a big breath. So, at that point you know she's alive," Linda told KPIX.
The woman was rushed to San Francisco General Hospital with a head injury.
The playground at Washington Square was roped off as crews moved in to investigate.
The tree in question, No. 56 on the city register, is a Canary Island pine. It was last fully examined in 2008, with another brief checkup in 2010 -- before the drought. It was reported to be in good condition.
"Looking at the tree itself, we've seen that it has good moisture content and that the wood is very healthy," said Dennis Kern, director of operations at S.F. Recreation and Parks.
Kern said that that a six-year interval between arborist evaluations is in line with urban forestry standards.
The injured woman lives in Visitacion Valley in San Francisco and was in critical condition Friday night.