The Denver Fire Department is investigating an explosion at a senior living center that caused a fire Wednesday morning.

A construction crew working near the main building hit a power line, causing an explosion that set a transformer on fire, fire officials said.

A fire and explosion were reported at a Denver-area assisted home facility on Wednesday morning. According to a social media post from the Denver Fire Department, crews responded to the fire around 11:30 a.m. local time. About a half hour later, the fire department said an explosion had been reported inside the same facility.

Eighty-seven residents were displaced after an explosion inside a nursing home in Denver, Colorado on Wednesday. Eight people were transported to the hospital and the severity of their injuries was not immediately shared. The cause of the explosion is still unknown at this time.