Complex sentence: When constructed, the pier extended 3.5 miles (5.6 km) into San Francisco Bay from the end of University Avenue; due to extensive filling of the bay and the creation of the Berkeley Marina, it presently extends only 2.5 miles (4.1 km).
Split into simpler sentences: When constructed, the pier extended 3.5 miles (5.6 km) into San Francisco Bay from the end of University Avenue. Due to extensive filling of the bay and the creation of the Berkeley Marina, it presently extends only 2.5 miles (4.1 km).