A 31-year-old man was treated at George Washington University Hospital yesterday after he shackled himself to the steering column of a pickup truck, drove the truck into the Reflecting Pool on the Mall and slashed his arms with a razor, U.S. Park Police said.

The man, who officials said was from Winterport, Maine, was in good condition at the hospital yesterday, a hospital spokesman said.

Maj. Donald Rogers of the Park Police said the man apparently was trying to commit suicide when he drove the truck into the east end of the pool between the Washington Monument and the Lincoln Memorial at 9:28 a.m. yesterday.

Park Police officers waded into the 3-foot-deep pool and used bolt cutters to cut the chain attaching his left leg to the steering column, Rogers said.

A number of slogans were written on the truck's side panels, Rogers said, including "It's not my choice," "Heaven is earth," and "Messiah." The man has been committed to mental institutions in the past, Rogers said.

George Washington University Hospital will make a preliminary decision on whether the man should be held for further observation at St. Elizabeths, Rogers said.