With the last maneuver planned for April 24th, the Messenger spacecraft will be officially out of fuel and unable to maintain proper orbit around planet Mercury.  Scientists expect the spacecraft to crash onto Mercury on April 30th.  Unfortunately the impact is expected on the opposite side of the planet, out of view from Earth’s observation posts.

I know for past spacecraft impacts such as those on the Moon, NASA had asked the amateur astronomy community to observe and record the impact.  Out of luck and out of reach this time…

Sources: SPACE.COM / NASA