Poor roots, water weight may have toppled tree onto children

AP News
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Posted: Aug 14, 2015 12:31 AM
Poor roots, water weight may have toppled tree onto children

PASADENA, Calif. (AP) — An 85-foot-tall tree that fell in a Pasadena park last month, injuring eight children, had root problems, was leaning and may have absorbed a heavy load of water from a recent storm, according to an arborist's report released Thursday.

The 75-year-old Italian stone pine toppled on July 28 in Brookside Park next to the Kidspace Children's Museum. It fell on a group of children taking part in a summer day camp.

Eight children ages 6 to 8 were hurt. Most had minor injuries, but a boy and girl were hospitalized for several days.

An independent arborist firm was called in to examine the tree.

In a report, JTL Consultants concluded that three lacked widespread anchoring roots, especially on the side that fell.

The arborists found no signs of root rot, although charcoal and ash in a hole on the underside of the tree indicated fire damage in the past, possibly from hot barbecue coals, the report said.

Some roots were girdled, meaning they were twisted around the main stem of the tree instead of spreading out.

"Girdling roots prevented the formation of a root crown and the formation of large anchoring roots. The roots left in the ground after the tree fell were girdled and relatively small. This condition resulted in the tree being poorly anchored in the ground," the report said.

The tree probably absorbed a lot of water from a storm that dumped 0.61 inches of rain in the area on July 19-20 after years of drought, according to the report.

"Trees uptake large amounts of water into their system through their roots and release the water through their leaves or needles, a process known as evapotranspiration. The Italian stone pine probably could not release water as quickly as it was taking water in, causing a substantial increase in weight throughout the tree," the report said.

The tree was also leaning slightly to the east, the direction in which it fell.

A lean "is not necessarily an indicator of an unstable tree," but combined with the extra water weight it probably contributed to the collapse, the report said.

City workers routinely inspect and care for Pasadena's trees. But none of the problems with the pine were visible "unless you want to uproot all the trees," city spokesman William Boyer said.