Gresham firefighters say the fire at the press box near the Reynolds High School track may be arson, but they have not determined a final cause.

The fire broke out at about 2 a.m. on May 10, damaging football, volleyball, track, and audio equipment.

PAST COVERAGE | Gresham Fire Dept. battles blaze at Reynolds High School

Gresham Fire said it will do a group site investigation in a few weeks.

Reynolds School District officials said they still don't have an estimate on the cost of damages. They are working with fire crews to remove some items on the lower level.

Gresham Fire has issued a $5,000 reward, saying they believe it was arson, the district said. Anyone with information is urged to call 800-452-7888 or get ahold of www.oregoniaai.org.