The bolt on the right is a 3/8" by 4" Rawl expansion bolt. It is the 2nd lead bolt on "Black's Crack" at Fire Crag. The first bolt on that route (also a 3/8" Rawl) recently pulled out during a lead fall. This was the second lead bolt failure at the crag in recent years. For comparison, on the left is a 1/2" Powers expansion bolt.
Bolt failures like the one on "Black's Crack" are actually predictable. Test data compiled by Duane Raleigh and printed in Climbing Magazine in 1992 reveals that these bolts have little holding power in soft rock like that at Fire Crags. In this case, the real-world result is even scarier than the data. The first bolt, which failed, was located 13 feet above the ground. The second bolt is located just 36-inches above the first bolt. The fall that resulted in the failure of the first bolt was therefore of a very low fall factor.