CHESAPEAKE, Va. (WVEC) -- Investigators determined that lightning was the cause of a 4-alarm fire that set a senior-living apartment facility on fire over the weekend, killing three people, injuring six more, and leaving about 150 residents without a place to stay.

One of the people killed was 61-year-old Cynthia Martenis.

The fire started Saturday around 4:30 a.m. Three of the five buildings went up in flames, and left others with significant amounts of damage.

The buildings where residents died did not have a fire alarm system. The buildings were constructed in the early 1990s, before the fire code required them.

City officials said that if people would like to make a monetary contribution to help survivors of the fire, they can make it to United Way or Red Cross.

A fund has been created through the donation page of the United Way of South Hampton Roads' website. Once there, people can check "Apply this gift to a specific program or cause," then select "Chesapeake Fire Victims" from the dropdown menu.

The City of Chesapeake opened a disaster resource center on July 20 with the primary goal of connecting residents with agencies that will provide clothing and furniture.

The center at New Galilee Baptist Church (1765 South Military Highway) opens at 9 a.m. daily and closes at 5 p.m. through July 23.

The president of Boyd Homes, David Rudiger, told 13News Now some residents have been allowed to move back into their apartments. Meanwhile 68 units are currently unlivable.

"On those 68 units where they will not be able to move back into their units we are processing their move out statements as quickly as possible. We have extra staff on site so that we can get them their pro-rated rent and refund whatever money is owed to them," said Rudiger.

He also said Boyd Homes is trying to get residents into some of their other properties.

"We've reached out to the Virginia Apartment Management Association to get us a list of available units for rent in the area so that we can past that list on to the displaced residents," said Rudiger.

Rudiger said they would help find alternative housing for the 26 residents Boyd Homes was assisting with hotel rooms Tuesday.

"We've transferred that over to social services and the Red Cross and they are working directly with those displaced persons," said Rudiger.

Rudiger also said their priority is to make sure the apartments are safe. They are working with several agencies to ensure this.

"We've been having the property inspected by The City and outside fire inspectors for years and no one has ever made any recommendations of that we needed to update this system. So we are reaching out now and asking for recommendations," said Rudiger.

PHOTOS: 4-alarm fire at Chesapeake senior living complex