The family of a Port Moody woman killed by a falling tree has filed a lawsuit against the Greater Vancouver Water District and two B.C. arborists, alleging they were negligent in dealing with dangerous trees near their property.

Jill Calder was asleep in her Alpine Drive home at around 6:30 a.m. on March 10, 2016 when a powerful windstorm sent a hemlock tree crashing through the roof and into the master bedroom, killing the 57-year-old.

Now, Calder's sons are suing the district and VanArbor Vegetation Consulting Ltd.—a company that provides advice on how to manage forested landscapes—saying they could have done more to protect residents in the wooded area. The second arborist is not named in the suit.

In the lawsuit, they allege their father had raised concerns at least twice about the trees nearby, including the hemlock, before it fell onto the house. The suit alleges the district sent crews to examine the trees on both occasions, but none were felled.

The sons claim that, three or four years before the windstorm, their father was told that "there was rot in the hemlock" and that it would be "catastrophic" if it fell. According to the civil claim, the tree was marked, but nothing else was done.

None of these allegations have been proven in court.

In a statement, the regional district said it launched a review of its tree management practices after Calder's death.

"We are diligent in maintaining our properties to the very best of our ability," the statement read.

VanArbor's lawyer told CTV News their client would not comment on the case as long as it's part of ongoing litigation.

The lawyer representing Calder's sons also said they do not wish to comment publicly.

Calder was a respected community leader in Port Moody. Prior to her death, she had spent 16 years working as the executive director of New View Society, a non-profit that provides employment opportunities to people with mental health issues.

The windstorm that led to her death also wreaked havoc throughout the region, prompting a warning from Environment Canada for Metro Vancouver, Fraser Valley, Sunshine Coast, Vancouver Island, Central Coast and Howe Sound.

Winds of up to 90 km/h flipped a Cessna aircraft in Pitt Meadows, tore the roof off a shed in Langley and cut power to 118,000 BC Hydro customers.

Neighbour Beth Thompson said city and regional district crews have since thinned out some of the woodland behind her home and did thorough inspections on other trees to make sure they weren't at risk of falling unexpectedly.

But while the trees in the area might be safer, Thompson said Calder's death has changed the neighbourhood forever.

"We feel very badly for our neigbour," she said. "When it's windy…you're conscious of it and it is in the back of your mind."

With files from CTV Vancouver's Maria Weisgarber