DENVER -- The man who owns the building that exploded in Denver's Baker neighborhood on Tuesday said there are seven units in the building.
Nine people were injured when the building was partially destroyed in an apparent natural gas explosion.
Seven people were treated for minor injuries. One man was critically injured and a woman who was pulled from the rubble is in stable condition.
The owner, who only identified himself as Tom, said 14 of the tenants were displaced, and he does not know whether the man who was critically injured was a tenant.
On Tuesday, the Denver Fire Department said it believes the explosion originated in Unit 368. The owner said he had been inside the unit within the past month and said he was confident there was no drug activity taking place in that unit.
Tom, who has owned the building for 40 years, said he learned about the explosion from the fire department.
He said he has been in touch with the American Red Cross and is working to contact and help all of his displaced tenants.
Xcel Energy said it had reviewed all incoming customer calls from the area during the hours before the incident and said it did not receive any gas-related calls.
Fire spokesman Greg Pixley said the incident is not being investigated as arson and there is no evidence of methamphetamine or marijuana use in the complex to suggest a possible cause.
Pixley said the fire is being called suspicious for the obvious reason that buildings do not normally explode.
There is no word on whether investigators will find the explosion was human caused, mechanical or something else.
The fire department said six of its fire investigators are working at the scene Wednesday.