SAN FRANCISCO (AP) — San Francisco fire officials say rescue crews recovered a body from the debris of a makeshift boat that crashed into a pier.

Fire spokeswoman Mindy Talmadge says a witness called authorities at 6:11 a.m. Wednesday to report that a plywood boat traveling at full throttle had crashed at Pier 52 in the city’s Mission Bay neighborhood.

Talmadge says the witness told fire officials he saw the boat driver slumped over the wheel shortly before the impact.

No one else was hurt. Fire officials are investigating what caused the crash.