A six-year-old boy is suing his former daycare and the Yukon government after he fell up to 4.5 metres (15 feet) onto a rock pile during a field trip at the government's main administration building.

Andrew Diego Sprokkreeff launched the legal action last week against the Tree House Play School, employee Emily Gallant and the government.

On Dec. 7, 2011, Tree House arranged for some of the children to attend a Christmas performance at the legislative building at 2071 Second Ave.

When the production ended, the four-year-old Diego stepped outside while Gallant, who was supervising him, remained inside nearby.

From the outdoor landing, the boy began to peer through the entrance.

"Diego saw someone approaching the glass doors from the interior of the YG building and stepped back to allow that person to exit through the glass doors,” the lawsuit states.

"When Diego stepped back, he fell through or under the railing on the landing next to the glass doors” — immediately to the left of the entrance as you approach it.

"Diego fell approximately 12 to 15 feet and landed on a rock pile below.”

He suffered cuts to his scalp, bruises and soft tissue injuries as well as "decreased ability to concentrate” and post-traumatic stress disorder, according to the suit.

"It's quite a drop to the walk below. It's quite horrific, actually,” James Tucker, Diego's lawyer, said in an interview.

The statement of claim points the finger at the government for having unsafe railings — ones that "permit a child to pass between them” — and failing to post adequate warning of "the hazard.”

Alternately, the plaintiff argues his fall resulted from the negligence of Gallant for failing "to adequately supervise Diego while he was in her care.”

The legal action also alleges Tree House may be at fault for negligence stemming from a failure to employ qualified staff or train them properly.

The government has installed more closely spaced railings since the incident.

"As a result of the fall and his injuries, Diego has suffered loss of enjoyment and amenities of life, pain and suffering,” according to the suit, filed last Friday.

He continues to receive medical treatment and therapy.

"Diego has lost his capacity to earn income (in) the future,” the suit adds.

He is claiming general and special damages, legal costs, and interest.

Diego's mother, Cheryl Buych, is acting on his behalf as legal guardian in the suit.

Residents of Whitehorse at the time of the accident, the family now lives in Faro.

The Department of Justice declined comment as the case is before the courts.

Gallant could not be reached for comment.

Tree House Play School is a daycare off Wann Road in Porter Creek.

"We have been in business for many years and take pride in serving the surrounding area,” the website states.

"All of our employees carry with them a wealth of experience to ensure professional results each and every time. We are not satisfied with our work until you are. And that's a guarantee.”

Owner Susan Langer declined to comment on the lawsuit.