Eight children were injured, two of them critically, after a huge pine tree collapsed at a summer day camp on Tuesday in Pasadena, California, the Associated Press (AP) reported, citing fire department officials. According to local reports, arborists will conduct an investigation to determine the cause of the tree collapse.

The 75-foot-tall, 75-year-old pine tree fell on the children outside the Kidspace Children's Museum in Pasadena's Brookside Park, city fire department spokeswoman Lisa Derderian said.

"It was the end of the day, so there were people gathered outside who were leaving and there was a camp group waiting for pickup by their parents when the tree came down,” Tim Scheidler, the museum's marketing manager, said, according to AP

The museum is scheduled to reopen as planned on Wednesday.

"There were some injuries at the time of the incident but all Kidspace staff, campers, volunteers, and guests were accounted for. Emergency services were immediately called and arrived on the scene shortly after," the museum wrote in a statement, on its Facebook page. "At this time, City of Pasadena officials have secured the scene and are investigating what may have caused the incident."

The fire department reportedly sent its urban search-and-rescue team to cut through the tree to ensure no one was trapped underneath. All the children injured in the incident were aged between 6 to 8 years.

"I myself saw two children carried out on stretchers and they were pretty bloody. That brought tears to my eyes," Hanna Lin of Altadena, who volunteers at the museum, told KABC-TV, according to AP. "Apparently they were doing arts and crafts directly under the tree when it fell on them."