A massive fire at a senior living community in Pennsylvania late Thursday caused the evacuation of residents, and the blaze reportedly injured at least 20 people, The Philadelphia Inquirer reported.

The fire was reported around 11 p.m. Thursday at Barclay Friends Senior Living Community in West Chester, the Inquirer reported. Residents were forced to evacuate outside into 40-degree temperatures.

At a 6:30 a.m. briefing, officials would not provide information about casualties, including whether anyone was dead or missing. They only reported that the fire was declared under control at 1:22 a.m. and that the cause is under investigation.

There were no reported injuries among firefighters,

“All I can tell you is we have multiple alarms and multiple evacuations,” said a Chester County dispatcher told the Inquirer, who confirmed some of the basic details.

The blaze climbed to five alarms in about half an hour, the Inquirer reported, and at one point flames rose above the tops of some of the buildings. The Barclay Friends facility offers offers various levels of care from memory care and skilled nursing to post-acute rehabilitation., Inquirer reported.

Fire officials said emergency responders were triaging patients on the lawn of the facility as the huge building burned with billowing, dense smoke.