PORTLAND, Ore. -- Fire investigators said they arrested a Portland State University student early Monday morning on an arson charge.

PSU student Paul Rowley was arrested on a charge of first-degree arson after a fire was set in a stairwell of a PSU residence hall at St. Helens Court, fire investigators said.

Firefighters arrived at 1131 SW Montgomery St. at about 4:30 a.m. and found the fire had been extinguished by one of the residents but not before the building was filled with smoke and alarms were activated, fire officials said.

Investigators said information from a witness led them to arrest Rowley on the arson charge, which is a Measure 11 crime that carries a minimum sentence of 90 months.

Several bundles of newspapers and phone books were found burned in a stairwell between the first and second floors. Investigators said this stairwell was one of two that would be used to escape a fire.

Firefighters said it took more than an hour to remove smoke from the building and reset the alarm system. All the doors from the stairway to each floor were propped open by residents. Fire officials said these doors are designed to keep a fire from spreading from floor to floor.